On 15.3.2022 10.43, Martin Kepplinger wrote: > Am Mittwoch, dem 09.03.2022 um 11:29 +0200 schrieb Mathias Nyman: >> On 9.3.2022 9.56, Martin Kepplinger wrote: >>> Am Dienstag, dem 08.03.2022 um 17:17 +0100 schrieb Martin >>> Kepplinger: >>>> Am Montag, dem 07.03.2022 um 10:49 +0200 schrieb Mathias Nyman: >>>>> On 4.3.2022 16.17, Greg KH wrote: >>>>>> On Fri, Mar 04, 2022 at 12:30:57PM +0100, Martin Kepplinger >>>>>> wrote: >>>>>>> On the Librem 5 imx8mq system we've seen the stop endpoint >>>>>>> command >>>>>>> time out regularly which results in the hub dying. >>>>>>> >>>>>>> While on the one hand we see "Port resume timed out, port >>>>>>> 1-1: >>>>>>> 0xfe3" >>>>>>> before this and on the other hand driver-comments suggest >>>>>>> that >>>>>>> the driver >>>>>>> might be able to recover instead of dying here, Sarah >>>>>>> seemed to >>>>>>> have a >>>>>>> workaround for this particulator problem in mind already: >>>>>>> >>>>>>> Make it a module parameter. So while it might not be the >>>>>>> root >>>>>>> cause for >>>>>>> the problem, do this to give users a workaround. >>>>>> >>>>>> This is not the 1990's, sorry, please do not add new module >>>>>> parameters. >>>>>> They modify code, when you want to modify an individual >>>>>> device. >>>>>> >>>>> >>>>> Agree, I think we really need to find the rootcause here. >>>>> >>>>> There's a known problem with this stop endpoint timeout timer. >>>>> >>>>> For all other commands we start the timer when the controller >>>>> starts >>>>> processing the >>>>> command, but the stop endpoint timer is started immediately >>>>> when >>>>> command is queued. >>>>> So it might timeout if some other commend before it failed. >>>>> >>>>> I have a patchseries for this. It's still work in progress but >>>>> should >>>>> be testable. >>>>> Pushed to a branch named stop_endpoint_fixes >>>>> >>>>> git://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git >>>>> stop_endpoint_fixes >>>>> https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=stop_endpoint_fixes >>>>> >>>>> Can you try it out and see if it helps? >>>>> >>>> >>>> thanks a lot Mathias, I'm running these now. The timeout has not >>>> been >>>> easy to reproduce (or I'm just lazy) but in a few days I should >>>> be >>>> able >>>> to tell whether that helps. >>>> >>>> So this thread has been about >>>> >>>> [14145.960512] xhci-hcd xhci-hcd.4.auto: Port resume timed out, >>>> port >>>> 1- >>>> 1: 0xfe3 >>>> [14156.308511] xhci-hcd xhci-hcd.4.auto: xHCI host not responding >>>> to >>>> stop endpoint command. >>>> >>>> that I previously tried to work around by increasing >>>> XHCI_MAX_REXIT_TIMEOUT_MS and XHCI_STOP_EP_CMD_TIMEOUT. >>>> >>>> >>>> These patches can't help with the following, right? >>>> readl_poll_timeout_atomic() with a fixed timeout is called in >>>> this >>>> case: >>>> >>>> xhci-hcd xhci-hcd.4.auto: Abort failed to stop command ring: -110 >>>> >>>> I see that too from time to time. It results in the HC dying as >>>> well. >>>> >>>> thanks, >>>> martin >>>> >>> >>> hi Mathias, >>> >>> I already saw "Port resume timed out" and the HC dying running your >>> patches. I append the logs. >>> >>> So for now I saw more success with increasing >>> XHCI_MAX_REXIT_TIMEOUT_MS. >>> >> >> XHCI_MAX_REXIT_TIMEOUT_MS is only 20ms, that we can probably change. >> >> Is 40ms enough? >> >> "Port resume timed out, port 1-1: 0xfe3" means port link state is >> still in >> resume even if we asked link to go to U0 20ms ago. >> >> Maybe this hw combination just resumes slowly. >> >> Thanks >> Mathias > > > hi Mathias, sorry for not responding until now. I'm currently testing > whether QUIRK_HUB_SLOW_RESET will work too to avoid the HC dying due to > the command timeouts: > > { USB_DEVICE(0x0424, 0x2640), .driver_info = USB_QUIRK_HUB_SLOW_RESET > }, > > But these timeouts usually happen after a port is reset (not just > runtime-resumed without resetting, which happens very often). > > And exactly *that* is what I now want to try to avoid now. I *never* > want ports on the Hub in question to be reset. (it causes enough other > hick-ups even *if* the reset would be successful and not result in the > HC die, so all resets need to go away). > > Normally, on successful runtime resume (without any reset), the hub > port status is: > > Mär 15 08:24:44.748852 pureos kernel: usb 1-1-port2: status 0503 change > 0004 > Mär 15 08:24:44.747863 pureos kernel: usb 1-1-port1: status 0507 change > 0000 > > But when the following happens: > > Mär 15 08:24:52.660348 pureos kernel: usb 1-1-port2: status 0101 change > 0005 > Mär 15 08:24:52.656107 pureos kernel: usb 1-1-port1: status 0507 change > 0000 > > then hub_activate() sets "reset_resume" (persist is enabled) and it's > too late :) > > Do you have an idea about what could be the cause for "status 0101" > here? (it basically means ENABLE and HIGH_SPEED is not set, but why?) > > I know this is a bit of a different area now, but it's all about > avoiding problems on that hub at runtime. > > thanks, > > martin Not sure about this. The failing case has change 0005, meaning the connect status change bit is set. Also HIGH_SPEED bit in status is only relevant when ENABLE bit is set. If there was a connect change detected then I guess port reset is needed to get the USB 2 port back to enable state. -Mathias
