From: Alan Stern <st...@rowland.harvard.edu>
3.4.108-rc1 review patch. If anyone has any objections, please let me know.
------------------
commit 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 upstream.
Currently the USB stack assumes that all host controller drivers are
capable of receiving wakeup requests from downstream devices.
However, this isn't true for the isp1760-hcd driver, which means that
it isn't safe to do a runtime suspend of any device attached to a
root-hub port if the device requires wakeup.
This patch adds a "cant_recv_wakeups" flag to the usb_hcd structure
and sets the flag in isp1760-hcd. The core is modified to prevent a
direct child of the root hub from being put into runtime suspend with
wakeup enabled if the flag is set.
Signed-off-by: Alan Stern <st...@rowland.harvard.edu>
Tested-by: Nicolas Pitre <n...@linaro.org>
Signed-off-by: Greg Kroah-Hartman <g...@kroah.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lize...@huawei.com>
---
drivers/usb/core/driver.c | 12 ++++++++++++
drivers/usb/host/isp1760-hcd.c | 3 +++
include/linux/usb/hcd.h | 1 +
3 files changed, 16 insertions(+)
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 35bc3ba..621ea00 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1686,6 +1686,18 @@ static int autosuspend_check(struct usb_device *udev)
dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
return -EOPNOTSUPP;
}
+
+ /*
+ * If the device is a direct child of the root hub and the HCD
+ * doesn't handle wakeup requests, don't allow autosuspend when
+ * wakeup is needed.
+ */
+ if (w && udev->parent == udev->bus->root_hub &&
+ bus_to_hcd(udev->bus)->cant_recv_wakeups) {
+ dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
+ return -EOPNOTSUPP;
+ }
+
udev->do_remote_wakeup = w;
return 0;
}
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index fc72d44..949303f 100644
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -2242,6 +2242,9 @@ struct usb_hcd *isp1760_register(phys_addr_t res_start,
resource_size_t res_len,
hcd->rsrc_start = res_start;
hcd->rsrc_len = res_len;
+ /* This driver doesn't support wakeup requests */
+ hcd->cant_recv_wakeups = 1;
+
ret = usb_add_hcd(hcd, irq, irqflags);
if (ret)
goto err_unmap;
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 6674ec0..feb77716 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -126,6 +126,7 @@ struct usb_hcd {
unsigned wireless:1; /* Wireless USB HCD */
unsigned authorized_default:1;
unsigned has_tt:1; /* Integrated TT in root hub */
+ unsigned cant_recv_wakeups:1;
unsigned int irq; /* irq allocated */
void __iomem *regs; /* device memory/io */
--
1.9.1
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