[PATCH v6] ehci: fix EHCI host controller initialization sequence
According to EHCI spec, EHCI HC clears USBSTS.HCHalted whenever
USBCMD.RS=1.
However, it is a good practice to wait some time after setting USBCMD.RS
(approximately 100ms) until USBSTS.HCHalted become zero.
Without this waiting, VirtualBox's EHCI virtual HC accidentally hangs
(see BugLink).
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211095
Acked-by: Alan Stern
Signed-off-by: Eugene Korenevsky
---
v1: initial patch
v2: add BugLink tag
v3: add Revieved-By tags (incorrect), restore `msleep(5)`
v4: remove Reviewed-By tags, restore reading from USBCMD prior to msleep,
adjust description
v5: add `patch changelog`
v6: add `Acked-by: Alan Stern ` tag
drivers/usb/host/ehci-hcd.c | 12
1 file changed, 12 insertions(+)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index e358ae17d51e..1926b328b6aa 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -574,6 +574,7 @@ static int ehci_run (struct usb_hcd *hcd)
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 temp;
u32 hcc_params;
+ int rc;
hcd->uses_new_polling = 1;
@@ -629,9 +630,20 @@ static int ehci_run (struct usb_hcd *hcd)
down_write(_cf_port_reset_rwsem);
ehci->rh_state = EHCI_RH_RUNNING;
ehci_writel(ehci, FLAG_CF, >regs->configured_flag);
+
+ /* Wait until HC become operational */
ehci_readl(ehci, >regs->command); /* unblock posted writes */
msleep(5);
+ rc = ehci_handshake(ehci, >regs->status, STS_HALT, 0, 100 * 1000);
+
up_write(_cf_port_reset_rwsem);
+
+ if (rc) {
+ ehci_err(ehci, "USB %x.%x, controller refused to start: %d\n",
+((ehci->sbrn & 0xf0)>>4), (ehci->sbrn & 0x0f), rc);
+ return rc;
+ }
+
ehci->last_periodic_enable = ktime_get_real();
temp = HC_VERSION(ehci, ehci_readl(ehci, >caps->hc_capbase));
--
2.20.1
[PATCH] [PATCH v7] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
Changes in v7: rename hub_check_descriptor_sanity -> hub_descriptor_is_sane
Changes in v6: more pedantic conversion from `int` to `bool`; fix comment
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'
drivers/usb/core/hub.c | 38 +-
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b8bb20d7acdb..0484cd348156 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1661,10 +1661,28 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static bool hub_descriptor_is_sane(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If the first endpoint is not interrupt IN, we'd better punt! */
+ if (!usb_endpoint_is_int_in(>endpoint[0].desc))
+ return false;
+
+return true;
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1739,25 +1757,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_descriptor_is_sane(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1784,7 +1788,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.13.1
[PATCH] [PATCH v7] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky
---
Changes in v7: rename hub_check_descriptor_sanity -> hub_descriptor_is_sane
Changes in v6: more pedantic conversion from `int` to `bool`; fix comment
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'
drivers/usb/core/hub.c | 38 +-
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b8bb20d7acdb..0484cd348156 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1661,10 +1661,28 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static bool hub_descriptor_is_sane(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If the first endpoint is not interrupt IN, we'd better punt! */
+ if (!usb_endpoint_is_int_in(>endpoint[0].desc))
+ return false;
+
+return true;
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1739,25 +1757,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_descriptor_is_sane(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1784,7 +1788,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.13.1
[PATCH v6] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
Changes in v6: more pedantic conversion from `int` to `bool`; fix comment
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'
drivers/usb/core/hub.c | 38 +-
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..dbebfe4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,28 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static bool hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If the first endpoint is not interrupt IN, we'd better punt! */
+ if (!usb_endpoint_is_int_in(>endpoint[0].desc))
+ return false;
+
+return true;
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1818,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1849,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
[PATCH v6] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky
---
Changes in v6: more pedantic conversion from `int` to `bool`; fix comment
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'
drivers/usb/core/hub.c | 38 +-
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..dbebfe4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,28 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static bool hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If the first endpoint is not interrupt IN, we'd better punt! */
+ if (!usb_endpoint_is_int_in(>endpoint[0].desc))
+ return false;
+
+return true;
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1818,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1849,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
Re: [PATCH v5] USB hub_probe: rework ugly goto-into-compound-statement
> Ok, I'm going to be really pedantic here and ask that you spell this
> last statement out:
>if (usb...)
> return true;
>return false;
>
> Also, the comment should say:
> /* If the first endpoint is not interrupt IN, we... */
>
It's better to inverse the condition and return false:
```
if (!usb...)
return false;
return true;
```
This is exactly what is said in the comment ("If the first endpoint...
we'd better punt!"). And does not break the composition of the entire
function (all `if` bodies return false, last statement is `return
true`).
--
Eugene
Re: [PATCH v5] USB hub_probe: rework ugly goto-into-compound-statement
> Ok, I'm going to be really pedantic here and ask that you spell this
> last statement out:
>if (usb...)
> return true;
>return false;
>
> Also, the comment should say:
> /* If the first endpoint is not interrupt IN, we... */
>
It's better to inverse the condition and return false:
```
if (!usb...)
return false;
return true;
```
This is exactly what is said in the comment ("If the first endpoint...
we'd better punt!"). And does not break the composition of the entire
function (all `if` bodies return false, last statement is `return
true`).
--
Eugene
[PATCH v5] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..1a316a1 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static bool hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc) != 0;
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
[PATCH v5] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky
---
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..1a316a1 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static bool hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc) != 0;
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
[PATCH v4] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Changes since v3: fix typo
Changes since v2: extract the code to static function
Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by'
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..b770c8d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return 0;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
[PATCH v4] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Changes since v3: fix typo
Changes since v2: extract the code to static function
Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by'
Signed-off-by: Eugene Korenevsky
---
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..b770c8d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return 0;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
[PATCH v3] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Changes since v2: extract the code to static function
Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by'
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..aca8e86 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 1 &&
+ desc->desc.bInterfaceSubClass != 2)
+ return 0;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
--
Eugene
[PATCH v3] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Changes since v2: extract the code to static function
Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by'
Signed-off-by: Eugene Korenevsky
---
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..aca8e86 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 1 &&
+ desc->desc.bInterfaceSubClass != 2)
+ return 0;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
--
Eugene
[PATCH v3 2/2] USB hub_probe: put initialization before usage
Minor optimization: move initialization immediately before usage.
This gives a chance for more accurate register allocation by the compiler.
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
drivers/usb/core/hub.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7a20980..c7f6b5f 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1742,7 +1742,6 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
struct usb_device *hdev;
struct usb_hub *hub;
- desc = intf->cur_altsetting;
hdev = interface_to_usbdev(intf);
/*
@@ -1813,6 +1812,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
+ desc = intf->cur_altsetting;
if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
--
2.10.2
[PATCH v3 2/2] USB hub_probe: put initialization before usage
Minor optimization: move initialization immediately before usage.
This gives a chance for more accurate register allocation by the compiler.
Signed-off-by: Eugene Korenevsky
---
drivers/usb/core/hub.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7a20980..c7f6b5f 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1742,7 +1742,6 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
struct usb_device *hdev;
struct usb_hub *hub;
- desc = intf->cur_altsetting;
hdev = interface_to_usbdev(intf);
/*
@@ -1813,6 +1812,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
+ desc = intf->cur_altsetting;
if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
--
2.10.2
[PATCH v3 1/2] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
drivers/usb/core/hub.c | 33 -
1 file changed, 16 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..7a20980 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,23 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 1 &&
+ desc->desc.bInterfaceSubClass != 2)
+ return 0;
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1813,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1844,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
[PATCH v3 1/2] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky
---
drivers/usb/core/hub.c | 33 -
1 file changed, 16 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..7a20980 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,23 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(>kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 1 &&
+ desc->desc.bInterfaceSubClass != 2)
+ return 0;
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(>endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1813,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
@@ -1845,7 +1844,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, >endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
Re: [PATCH v2] USB hub_probe: remove ugly goto-into-compound-statement
On Mon, Nov 07, 2016 at 10:09:17AM +0100, Greg Kroah-Hartman wrote:
> > Rework smelling code (goto inside compound statement). Perhaps this is
> > legacy.
> > Anyway such code is not appropriate for Linux kernel.
> >
> > Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
> > ---
> > drivers/usb/core/hub.c | 24 +++-
> > 1 file changed, 11 insertions(+), 13 deletions(-)
>
> What changed from v1?
Fixed faults: missed 'Signed-off-by', spaces instead of tab.
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> > index cbb1467..4081672 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -1802,23 +1802,21 @@ static int hub_probe(struct usb_interface *intf,
> > const struct usb_device_id *id)
> >
> > /* Some hubs have a subclass of 1, which AFAICT according to the */
> > /* specs is not defined, but it works */
> > - if ((desc->desc.bInterfaceSubClass != 0) &&
> > - (desc->desc.bInterfaceSubClass != 1)) {
> > -descriptor_error:
> > +
> > + /* Reject in following cases:
> > +* - Interface subclass is not 0 or 1
> > +* - Multiple endpoints
> > +* - Not an interrupt in endpoint
> > +*/
> > + endpoint = >endpoint[0].desc;
> > + if ((desc->desc.bInterfaceSubClass != 0 &&
> > +desc->desc.bInterfaceSubClass != 1) ||
> > + desc->desc.bNumEndpoints != 1 ||
> > + !usb_endpoint_is_int_in(endpoint)) {
> > dev_err(>dev, "bad descriptor, ignoring hub\n");
> > return -EIO;
> > }
> >
> > - /* Multiple endpoints? What kind of mutant ninja-hub is this? */
> > - if (desc->desc.bNumEndpoints != 1)
> > - goto descriptor_error;
> > -
> > - endpoint = >endpoint[0].desc;
> > -
> > - /* If it's not an interrupt in endpoint, we'd better punt! */
> > - if (!usb_endpoint_is_int_in(endpoint))
> > - goto descriptor_error;
> > -
>
> As "horrible" as the original code might be, it's much easier to read
> and follow, which is the key thing here, right? What's so bad about a
> goto backwards?
OK, this patch is still not perfect. But jumping *back* into
*compound* *statement* hurts reader's eyes. Really. Maybe it's better to
extract this code to static function, compiler will inline it. See v3
patchset.
--
Eugene
Re: [PATCH v2] USB hub_probe: remove ugly goto-into-compound-statement
On Mon, Nov 07, 2016 at 10:09:17AM +0100, Greg Kroah-Hartman wrote:
> > Rework smelling code (goto inside compound statement). Perhaps this is
> > legacy.
> > Anyway such code is not appropriate for Linux kernel.
> >
> > Signed-off-by: Eugene Korenevsky
> > ---
> > drivers/usb/core/hub.c | 24 +++-
> > 1 file changed, 11 insertions(+), 13 deletions(-)
>
> What changed from v1?
Fixed faults: missed 'Signed-off-by', spaces instead of tab.
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> > index cbb1467..4081672 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -1802,23 +1802,21 @@ static int hub_probe(struct usb_interface *intf,
> > const struct usb_device_id *id)
> >
> > /* Some hubs have a subclass of 1, which AFAICT according to the */
> > /* specs is not defined, but it works */
> > - if ((desc->desc.bInterfaceSubClass != 0) &&
> > - (desc->desc.bInterfaceSubClass != 1)) {
> > -descriptor_error:
> > +
> > + /* Reject in following cases:
> > +* - Interface subclass is not 0 or 1
> > +* - Multiple endpoints
> > +* - Not an interrupt in endpoint
> > +*/
> > + endpoint = >endpoint[0].desc;
> > + if ((desc->desc.bInterfaceSubClass != 0 &&
> > +desc->desc.bInterfaceSubClass != 1) ||
> > + desc->desc.bNumEndpoints != 1 ||
> > + !usb_endpoint_is_int_in(endpoint)) {
> > dev_err(>dev, "bad descriptor, ignoring hub\n");
> > return -EIO;
> > }
> >
> > - /* Multiple endpoints? What kind of mutant ninja-hub is this? */
> > - if (desc->desc.bNumEndpoints != 1)
> > - goto descriptor_error;
> > -
> > - endpoint = >endpoint[0].desc;
> > -
> > - /* If it's not an interrupt in endpoint, we'd better punt! */
> > - if (!usb_endpoint_is_int_in(endpoint))
> > - goto descriptor_error;
> > -
>
> As "horrible" as the original code might be, it's much easier to read
> and follow, which is the key thing here, right? What's so bad about a
> goto backwards?
OK, this patch is still not perfect. But jumping *back* into
*compound* *statement* hurts reader's eyes. Really. Maybe it's better to
extract this code to static function, compiler will inline it. See v3
patchset.
--
Eugene
[PATCH v2] USB hub_probe: remove ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is legacy.
Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky <ekorenev...@gmail.com>
---
drivers/usb/core/hub.c | 24 +++-
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..4081672 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1802,23 +1802,21 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
/* Some hubs have a subclass of 1, which AFAICT according to the */
/* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+
+ /* Reject in following cases:
+* - Interface subclass is not 0 or 1
+* - Multiple endpoints
+* - Not an interrupt in endpoint
+*/
+ endpoint = >endpoint[0].desc;
+ if ((desc->desc.bInterfaceSubClass != 0 &&
+desc->desc.bInterfaceSubClass != 1) ||
+ desc->desc.bNumEndpoints != 1 ||
+ !usb_endpoint_is_int_in(endpoint)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
--
2.10.2
[PATCH v2] USB hub_probe: remove ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is legacy.
Anyway such code is not appropriate for Linux kernel.
Signed-off-by: Eugene Korenevsky
---
drivers/usb/core/hub.c | 24 +++-
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..4081672 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1802,23 +1802,21 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
/* Some hubs have a subclass of 1, which AFAICT according to the */
/* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+
+ /* Reject in following cases:
+* - Interface subclass is not 0 or 1
+* - Multiple endpoints
+* - Not an interrupt in endpoint
+*/
+ endpoint = >endpoint[0].desc;
+ if ((desc->desc.bInterfaceSubClass != 0 &&
+desc->desc.bInterfaceSubClass != 1) ||
+ desc->desc.bNumEndpoints != 1 ||
+ !usb_endpoint_is_int_in(endpoint)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
--
2.10.2
[PATCH] USB hub_probe: refactor ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is legacy.
Anyway such code is not appropriate for Linux kernel.
---
drivers/usb/core/hub.c | 24 +++-
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..abd786b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1802,23 +1802,21 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
/* Some hubs have a subclass of 1, which AFAICT according to the */
/* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+
+ /* Reject in following cases:
+* - Interface subclass is not 0 or 1
+* - Multiple endpoints
+* - Not an interrupt in endpoint
+*/
+ endpoint = >endpoint[0].desc;
+ if ((desc->desc.bInterfaceSubClass != 0 &&
+desc->desc.bInterfaceSubClass != 1) ||
+desc->desc.bNumEndpoints != 1 ||
+!usb_endpoint_is_int_in(endpoint)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
--
2.10.2
[PATCH] USB hub_probe: refactor ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is legacy.
Anyway such code is not appropriate for Linux kernel.
---
drivers/usb/core/hub.c | 24 +++-
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..abd786b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1802,23 +1802,21 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
/* Some hubs have a subclass of 1, which AFAICT according to the */
/* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+
+ /* Reject in following cases:
+* - Interface subclass is not 0 or 1
+* - Multiple endpoints
+* - Not an interrupt in endpoint
+*/
+ endpoint = >endpoint[0].desc;
+ if ((desc->desc.bInterfaceSubClass != 0 &&
+desc->desc.bInterfaceSubClass != 1) ||
+desc->desc.bNumEndpoints != 1 ||
+!usb_endpoint_is_int_in(endpoint)) {
dev_err(>dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = >endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(>dev, "USB hub found\n");
--
2.10.2
[PATCH] EFI loader: remove pointless "if" statement
An obvious cleanup. "if" statement does nothing and should be removed. --- arch/x86/boot/compressed/eboot.c | 6 +- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index cc69e37..202f2aa 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -1054,11 +1054,7 @@ static efi_status_t exit_boot(struct boot_params *boot_params, /* Historic? */ boot_params->alt_mem_k = 32 * 1024; - status = setup_e820(boot_params, e820ext, e820ext_size); - if (status != EFI_SUCCESS) - return status; - - return EFI_SUCCESS; + return setup_e820(boot_params, e820ext, e820ext_size); } /* -- 2.10.2
[PATCH] EFI loader: remove pointless "if" statement
An obvious cleanup. "if" statement does nothing and should be removed. --- arch/x86/boot/compressed/eboot.c | 6 +- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index cc69e37..202f2aa 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -1054,11 +1054,7 @@ static efi_status_t exit_boot(struct boot_params *boot_params, /* Historic? */ boot_params->alt_mem_k = 32 * 1024; - status = setup_e820(boot_params, e820ext, e820ext_size); - if (status != EFI_SUCCESS) - return status; - - return EFI_SUCCESS; + return setup_e820(boot_params, e820ext, e820ext_size); } /* -- 2.10.2
Re: [PATCH v2] EFI loader: remove redundant code
> > *e820ext is always NULL in 'alloc_e820ext()' (see the code of
> > 'exit_boot()').
> > Without loss of generality we can replace freeing with returning
> > EFI_INVALID_PARAMETER. So if the caller would ever incorrectly pass non-NULL
> > *e820ext, he will obtain a returned error code.
> >
>
> What exactly are you trying to fix here? Adding new artificial failure
> modes is hardly worth it when all you are doing is cleaning up code
> that by itself is correct to begin with, but is simply never called.
This code (free_pool, assignments) is dead whether it is correct or
not. So it is to be removed.
The check gives some assurance that memory is not leaked if the calling
code is changed.
> > @@ -956,11 +956,8 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct
> > setup_data **e820ext,
> > size = sizeof(struct setup_data) +
> > sizeof(struct e820entry) * nr_desc;
> >
> > - if (*e820ext) {
> > - efi_call_early(free_pool, *e820ext);
> > - *e820ext = NULL;
> > - *e820ext_size = 0;
> > - }
> > + if (*e820ext)
> > + return EFI_INVALID_PARAMETER;
> >
> > status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
> > size, (void **)e820ext);
> > --
--
Eugene
Re: [PATCH v2] EFI loader: remove redundant code
> > *e820ext is always NULL in 'alloc_e820ext()' (see the code of
> > 'exit_boot()').
> > Without loss of generality we can replace freeing with returning
> > EFI_INVALID_PARAMETER. So if the caller would ever incorrectly pass non-NULL
> > *e820ext, he will obtain a returned error code.
> >
>
> What exactly are you trying to fix here? Adding new artificial failure
> modes is hardly worth it when all you are doing is cleaning up code
> that by itself is correct to begin with, but is simply never called.
This code (free_pool, assignments) is dead whether it is correct or
not. So it is to be removed.
The check gives some assurance that memory is not leaked if the calling
code is changed.
> > @@ -956,11 +956,8 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct
> > setup_data **e820ext,
> > size = sizeof(struct setup_data) +
> > sizeof(struct e820entry) * nr_desc;
> >
> > - if (*e820ext) {
> > - efi_call_early(free_pool, *e820ext);
> > - *e820ext = NULL;
> > - *e820ext_size = 0;
> > - }
> > + if (*e820ext)
> > + return EFI_INVALID_PARAMETER;
> >
> > status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
> > size, (void **)e820ext);
> > --
--
Eugene
Re: [PATCH] EFI loader: remove dead code
Applied your notice. Sent v2 patch. -- Eugene
Re: [PATCH] EFI loader: remove dead code
Applied your notice. Sent v2 patch. -- Eugene
[PATCH v2] EFI loader: remove redundant code
*e820ext is always NULL in 'alloc_e820ext()' (see the code of 'exit_boot()').
Without loss of generality we can replace freeing with returning
EFI_INVALID_PARAMETER. So if the caller would ever incorrectly pass non-NULL
*e820ext, he will obtain a returned error code.
---
arch/x86/boot/compressed/eboot.c | 7 ++-
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index cc69e37..6cc66c7 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -956,11 +956,8 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct
setup_data **e820ext,
size = sizeof(struct setup_data) +
sizeof(struct e820entry) * nr_desc;
- if (*e820ext) {
- efi_call_early(free_pool, *e820ext);
- *e820ext = NULL;
- *e820ext_size = 0;
- }
+ if (*e820ext)
+ return EFI_INVALID_PARAMETER;
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size, (void **)e820ext);
--
2.10.2
[PATCH v2] EFI loader: remove redundant code
*e820ext is always NULL in 'alloc_e820ext()' (see the code of 'exit_boot()').
Without loss of generality we can replace freeing with returning
EFI_INVALID_PARAMETER. So if the caller would ever incorrectly pass non-NULL
*e820ext, he will obtain a returned error code.
---
arch/x86/boot/compressed/eboot.c | 7 ++-
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index cc69e37..6cc66c7 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -956,11 +956,8 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct
setup_data **e820ext,
size = sizeof(struct setup_data) +
sizeof(struct e820entry) * nr_desc;
- if (*e820ext) {
- efi_call_early(free_pool, *e820ext);
- *e820ext = NULL;
- *e820ext_size = 0;
- }
+ if (*e820ext)
+ return EFI_INVALID_PARAMETER;
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size, (void **)e820ext);
--
2.10.2
[PATCH] EFI loader: remove dead code
*e820ext is always NULL in 'alloc_e820ext()' (see the code of 'exit_boot()').
Therefore the 'if' condition is always false and the entire 'if' statement is
pointless. Remove it.
---
arch/x86/boot/compressed/eboot.c | 6 --
1 file changed, 6 deletions(-)
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index cc69e37..edfd4d6 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -956,12 +956,6 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct
setup_data **e820ext,
size = sizeof(struct setup_data) +
sizeof(struct e820entry) * nr_desc;
- if (*e820ext) {
- efi_call_early(free_pool, *e820ext);
- *e820ext = NULL;
- *e820ext_size = 0;
- }
-
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size, (void **)e820ext);
if (status == EFI_SUCCESS)
--
2.10.2
[PATCH] EFI loader: remove dead code
*e820ext is always NULL in 'alloc_e820ext()' (see the code of 'exit_boot()').
Therefore the 'if' condition is always false and the entire 'if' statement is
pointless. Remove it.
---
arch/x86/boot/compressed/eboot.c | 6 --
1 file changed, 6 deletions(-)
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index cc69e37..edfd4d6 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -956,12 +956,6 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct
setup_data **e820ext,
size = sizeof(struct setup_data) +
sizeof(struct e820entry) * nr_desc;
- if (*e820ext) {
- efi_call_early(free_pool, *e820ext);
- *e820ext = NULL;
- *e820ext_size = 0;
- }
-
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
size, (void **)e820ext);
if (status == EFI_SUCCESS)
--
2.10.2
