On Thu, May 13, 2021 at 12:14:45PM +0800, chris.chiu@xxxxxxxxxxxxx wrote:
> From: Chris Chiu <chris.chiu@xxxxxxxxxxxxx>
>
> On the Realtek high-speed Hub(0bda:5487), the port which has wakeup
> enabled_descendants will sometimes timeout when setting PORT_SUSPEND
> feature. After checking the PORT_SUSPEND bit in wPortStatus, it is
> already set. However, the hub will fail to activate because the
> PORT_SUSPEND feature of that port is not cleared during resume. All
> connected devices are lost after resume.
The last two sentences of this paragraph are now inaccurate. Please fix
them up to match the current patch version.
> Check the port status to verify whether it's really suspended when
> timeout happpens. If yes, mark it as suspended so the device can
> be resumed correctly.
>
> Signed-off-by: Chris Chiu <chris.chiu@xxxxxxxxxxxxx>
> ---
>
> Changelog:
> v3:
> - create a new goto target for the timeout case instead of
> reset_resume
> - Revise the commit title/message because reset_resume is not
> required.
> v2:
> - create a new variable to keep the result of hub_port_status
> when suspend timeout.
>
> drivers/usb/core/hub.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index b2bc4b7c4289..c5d64175eaa9 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -3385,6 +3385,21 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
> status = 0;
> }
> if (status) {
> + if (status == -ETIMEDOUT) {
> + u16 portstatus, portchange;
> +
Extra blank line.
> + int ret = hub_port_status(hub, port1, &portstatus,
> + &portchange);
> +
> + dev_dbg(&port_dev->dev,
> + "suspend timeout, status %04x\n", portstatus);
The portstatus value shouldn't be printed if ret < 0, because it won't
be initialized. If you want, initialize portstatus to 0 in the
declaration.
Also, there should be a comment here explaining why this code is needed.
It should say pretty the same thing as the patch description, but more
briefly (two sentences should be sufficient).
Alan Stern
> +
> + if (ret == 0 && port_is_suspended(hub, portstatus)) {
> + status = 0;
> + goto suspend_done;
> + }
> + }
> +
> dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
>
> /* Try to enable USB3 LTM again */
> @@ -3401,6 +3416,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
> if (!PMSG_IS_AUTO(msg))
> status = 0;
> } else {
> + suspend_done:
> dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
> (PMSG_IS_AUTO(msg) ? "auto-" : ""),
> udev->do_remote_wakeup);
> --
> 2.20.1
>
