On 04/22/2014 07:27 AM, Pratyush Anand wrote:
As best case, a host controller should support U0 to U1 switching for
the devices connected below any tier of hub level supported by usb
specification. Therefore xhci_check_tier_policy should always return
success as default implementation.
A host should be able to issue LGO_Ux after the timeout calculated as
per definition of system exit latency defined in C.1.5.2. Therefore
xhci_calculate_ux_timeout returns ux_params.sel as the default
implementation.
Use default calculation in absence of any vendor specific limitations.
Signed-off-by: Pratyush Anand <pratyush.an...@st.com>
Tested-by: Aymen Bouattay <aymen.bouat...@st.com>
---
drivers/usb/host/xhci.c | 66 +++++++++++++++++++++++++++++++++++--------------
1 file changed, 48 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6cc58fe..f5ac76a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4140,8 +4140,7 @@ static u16 xhci_get_timeout_no_hub_lpm(struct usb_device
*udev,
return USB3_LPM_DISABLED;
}
-/* Returns the hub-encoded U1 timeout value.
- * The U1 timeout should be the maximum of the following values:
+/* The U1 timeout should be the maximum of the following values:
* - For control endpoints, U1 system exit latency (SEL) * 3
* - For bulk endpoints, U1 SEL * 5
* - For interrupt endpoints:
@@ -4149,7 +4148,8 @@ static u16 xhci_get_timeout_no_hub_lpm(struct usb_device
*udev,
* - Periodic EPs, max(105% of bInterval, U1 SEL * 2)
* - For isochronous endpoints, max(105% of bInterval, U1 SEL * 2)
*/
-static u16 xhci_calculate_intel_u1_timeout(struct usb_device *udev,
+static unsigned long long xhci_calculate_intel_u1_timeout(
+ struct usb_device *udev,
struct usb_endpoint_descriptor *desc)
{
unsigned long long timeout_ns;
@@ -4181,11 +4181,28 @@ static u16 xhci_calculate_intel_u1_timeout(struct
usb_device *udev,
return 0;
}
- /* The U1 timeout is encoded in 1us intervals. */
- timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 1000);
- /* Don't return a timeout of zero, because that's USB3_LPM_DISABLED. */
+ return timeout_ns;
+}
+
+/* Returns the hub-encoded U1 timeout value. */
+static u16 xhci_calculate_u1_timeout(struct xhci_hcd *xhci,
+ struct usb_device *udev,
+ struct usb_endpoint_descriptor *desc)
+{
+ unsigned long long timeout_ns;
+
+ if (xhci->quirks & XHCI_INTEL_HOST)
+ timeout_ns = xhci_calculate_intel_u1_timeout(udev, desc);
+ else
+ timeout_ns = udev->u1_params.sel;
+
+ /* The U1 timeout is encoded in 1us intervals.
+ * Don't return a timeout of zero, because that's USB3_LPM_DISABLED.
+ */
if (timeout_ns == USB3_LPM_DISABLED)
- timeout_ns++;
+ timeout_ns = 1;
+ else
+ timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 1000);
/* If the necessary timeout value is bigger than what we can set in the
* USB 3.0 hub, we have to disable hub-initiated U1.
@@ -4197,14 +4214,14 @@ static u16 xhci_calculate_intel_u1_timeout(struct
usb_device *udev,
return xhci_get_timeout_no_hub_lpm(udev, USB3_LPM_U1);
}
-/* Returns the hub-encoded U2 timeout value.
- * The U2 timeout should be the maximum of:
+/* The U2 timeout should be the maximum of:
* - 10 ms (to avoid the bandwidth impact on the scheduler)
* - largest bInterval of any active periodic endpoint (to avoid going
* into lower power link states between intervals).
* - the U2 Exit Latency of the device
*/
-static u16 xhci_calculate_intel_u2_timeout(struct usb_device *udev,
+static unsigned long long xhci_calculate_intel_u2_timeout(
+ struct usb_device *udev,
struct usb_endpoint_descriptor *desc)
{
unsigned long long timeout_ns;
@@ -4220,6 +4237,21 @@ static u16 xhci_calculate_intel_u2_timeout(struct
usb_device *udev,
if (u2_del_ns > timeout_ns)
timeout_ns = u2_del_ns;
+ return timeout_ns;
+}
+
+/* Returns the hub-encoded U2 timeout value. */
+static u16 xhci_calculate_u2_timeout(struct xhci_hcd *xhci,
+ struct usb_device *udev,
+ struct usb_endpoint_descriptor *desc)
+{
+ unsigned long long timeout_ns;
+
+ if (xhci->quirks & XHCI_INTEL_HOST)
+ timeout_ns = xhci_calculate_intel_u2_timeout(udev, desc);
+ else
+ timeout_ns = udev->u2_params.sel;
+
/* The U2 timeout is encoded in 256us intervals */
timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 256 * 1000);
/* If the necessary timeout value is bigger than what we can set in the
@@ -4238,13 +4270,10 @@ static u16
xhci_call_host_update_timeout_for_endpoint(struct xhci_hcd *xhci,
enum usb3_link_state state,
u16 *timeout)
{
- if (state == USB3_LPM_U1) {
- if (xhci->quirks & XHCI_INTEL_HOST)
- return xhci_calculate_intel_u1_timeout(udev, desc);
- } else {
- if (xhci->quirks & XHCI_INTEL_HOST)
- return xhci_calculate_intel_u2_timeout(udev, desc);
- }
+ if (state == USB3_LPM_U1)
+ return xhci_calculate_u1_timeout(xhci, udev, desc);
+ else
+ return xhci_calculate_u2_timeout(xhci, udev, desc);
return USB3_LPM_DISABLED;
Tiny nitpick, but this last return doesn't do much here.
either:
if (state == USB3_LPM_U1)
return xhci_calculate_u1..
return xhci_calculate_u2...
or then:
if (state == USB3_LPM_U1)
return xhci_claculate_u1...
else if (state == USB3_LPM_U2) /* or just if (state == USB_LPM_U2) */
return xhci_calculate_u2..
return USB3_LPM_DISABLED
-Mathias
--
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