On Fri, Jul 07, 2017 at 11:56:53AM -0400, Alan Stern wrote:
> On Fri, 7 Jul 2017, Bin Liu wrote:
>
> > While unlink an urb, if the urb has been programmed in the controller,
> > the controller driver might do some hw related actions to tear down the
> > urb.
> >
> > Currently usb_hcd_flush_endpoint() passes each urb from the head of the
> > endpoint's urb_list to the controller driver, which could make the
> > controller driver think each urb has been programmed and take the
> > unnecessary actions for each urb.
> >
> > This patch changes the behavior in usb_hcd_flush_endpoint() to pass the
> > urbs from the tail of the list, to avoid any unnecessary actions in an
> > controller driver.
> >
> > Signed-off-by: Bin Liu <b-liu@xxxxxx>
> > ---
> > drivers/usb/core/hcd.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> > index 5dea98358c05..6839c176c701 100644
> > --- a/drivers/usb/core/hcd.c
> > +++ b/drivers/usb/core/hcd.c
> > @@ -1878,7 +1878,7 @@ void usb_hcd_flush_endpoint(struct usb_device *udev,
> > /* No more submits can occur */
> > spin_lock_irq(&hcd_urb_list_lock);
> > rescan:
> > - list_for_each_entry (urb, &ep->urb_list, urb_list) {
> > + list_for_each_entry_reverse (urb, &ep->urb_list, urb_list) {
> > int is_in;
> >
> > if (urb->unlinked)
>
> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Hi Alan, do you see any issue to tag this for stable v4.4+, in which
the issue that [PATCH 2/2] tries to solve is introduced?
Regards,
-Bin.
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