On 1 December 2016 at 14:04, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote: > Hi Baolu, > > On 1 December 2016 at 13:45, Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote: >> Hi, >> >> On 11/30/2016 05:02 PM, Baolin Wang wrote: >>> If the hardware never responds to the stop endpoint command, the >>> URBs will never be completed, and we might hang the USB subsystem. >>> The original watchdog timer is used to watch if one stop endpoint >>> command is timeout, if timeout, then the watchdog timer will set >>> XHCI_STATE_DYING, try to halt the xHCI host, and give back all >>> pending URBs. >>> >>> But now we already have one command timer to control command timeout, >>> thus we can also use the command timer to watch the stop endpoint >>> command, instead of one duplicate watchdog timer which need to be >>> removed. >>> >>> Meanwhile we don't need the 'stop_cmds_pending' flag to identy if >>> this is the last stop endpoint command of one endpoint. Since we >>> can make sure we only set one stop endpoint command for one endpoint >>> by 'EP_HALT_PENDING' flag in xhci_urb_dequeue() function. Thus remove >>> this flag. >> >> I am afraid you can't do this. "stop_cmds_pending" was added >> to fix the problem described in the comments that you want to >> remove. But I didn't find any fix of this problem in your patch. > > Now we can not pending another stop endpoint command for the same one > endpoint, since will check 'EP_HALT_PENDING' flag in > xhci_urb_dequeue() function to avoid this. But after some > investigation, I think I missed the stop endpoint command in > xhci_stop_device() which did not check the 'EP_HALT_PENDING' flag, > maybe need to add 'EP_HALT_PENDING' flag checking in > xhci_stop_device() function. DId I miss something else? Thanks. Sorry, wait, we will wait for the stop endpoint command finished in xhci_stop_device() function. So we don't need check 'EP_HALT_PENDING' flag as the orignal code did. -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
