Messages in this thread | | | Date | Mon, 10 Oct 2022 13:04:53 +0200 | Subject | Re: [PATCH v2 2/2] Revert "usb: dwc3: Don't switch OTG -> peripheral if extcon is present" | From | Ferry Toth <> |
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Hi
On 10-10-2022 07:02, Andrey Smirnov wrote: > On Fri, Oct 7, 2022 at 6:07 AM Ferry Toth <fntoth@gmail.com> wrote: >> >> On 07-10-2022 04:11, Thinh Nguyen wrote: >>> On Thu, Oct 06, 2022, Ferry Toth wrote: >>>> Hi >>>> >>>> On 06-10-2022 04:12, Thinh Nguyen wrote: >>>>> On Wed, Oct 05, 2022, Ferry Toth wrote: >>>>>> Hi, >>>>>> >>>>>> Thanks! >>>>>> >>>>>> Does the failure only happen the first time host is initialized? Or can >>>>>> it recover after switching to device then back to host mode? >>>>>> >>>>>> I can switch back and forth and device mode works each time, host mode remains >>>>>> dead. >>>>> Ok. >>>>> >>>>>> Probably the failure happens if some step(s) in dwc3_core_init() hasn't >>>>>> completed. >>>>>> >>>>>> tusb1210 is a phy driver right? The issue is probably because we didn't >>>>>> initialize the phy yet. So, I suspect placing dwc3_get_extcon() after >>>>>> initializing the phy will probably solve the dependency problem. >>>>>> >>>>>> You can try something for yourself or I can provide something to test >>>>>> later if you don't mind (maybe next week if it's ok). >>>>>> >>>>>> Yes, the code move I mentioned above "moves dwc3_get_extcon() until after >>>>>> dwc3_core_init() but just before dwc3_core_init_mode(). AFAIU initially >>>>>> dwc3_get_extcon() was called from within dwc3_core_init_mode() but only for >>>>>> case USB_DR_MODE_OTG. So with this change order of events is more or less >>>>>> unchanged" solves the issue. >>>>>> >>>>> I saw the experiment you did from the link you provided. We want to also >>>>> confirm exactly which step in dwc3_core_init() was needed. >>>> Ok. I first tried the code move suggested by Andrey (didn't work). Then >>>> after reading the actual code I moved a bit further. >>>> >>>> This move was on top of -rc6 without any reverts. I did not make additional >>>> changes to dwc3_core_init() >>>> >>>> So current v6.0 has: dwc3_get_extcon - dwc3_get_dr_mode - ... - >>>> dwc3_core_init - .. - dwc3_core_init_mode (not working) >>>> >>>> I changed to: dwc3_get_dr_mode - dwc3_get_extcon - .. - dwc3_core_init - .. >>>> - dwc3_core_init_mode (no change) >>>> >>>> Then to: dwc3_get_dr_mode - .. - dwc3_core_init - .. - dwc3_get_extcon - >>>> dwc3_core_init_mode (works) >>>> >>>> .. are what I believe for this issue irrelevant calls to >>>> dwc3_alloc_scratch_buffers, dwc3_check_params and dwc3_debugfs_init. >>>> >>> Right. Thanks for narrowing it down. There are still many steps in >>> dwc3_core_init(). We have some suspicion, but we still haven't confirmed >>> the exact cause of the failure. We can write a proper patch once we know >>> the reason. >> If you would like me to test your suspicion, just tell me what to do :-) > > OK, Ferry, I think I'm going to need clarification on specifics on > your test setup. Can you share your kernel config, maybe your > "/proc/config.gz", somewhere? When you say you are running vanilla > Linux, do you mean it or do you mean vanilla tree + some patch delta?
For v6.0 I can get the exacts tonight. But earlier I had this for v5.17:
https://github.com/htot/meta-intel-edison/blob/master/meta-intel-edison-bsp/recipes-kernel/linux/linux-yocto_5.17.bb
There are 2 patches referred in #67 and #68. One is related to the infinite loop. The other is I believe also needed to get dwc3 to work.
All the kernel config are applied as .cfg.
Patches and cfs's here:
https://github.com/htot/meta-intel-edison/tree/master/meta-intel-edison-bsp/recipes-kernel/linux/files
> The reason I'm asking is because I'm having a hard time reproducing > the problem on my end. In fact, when I build v6.0 > (4fe89d07dcc2804c8b562f6c7896a45643d34b2f) and then do a > > git revert 8bd6b8c4b100 0f0101719138 (original revert proposed by Andy) > > I get an infinite loop of reprobing that looks something like (some > debug tracing, function name + line number, included): > > [ 6.160732] tusb1210 dwc3.0.auto.ulpi: error -110 writing val 0x41 > to reg 0x80 > [ 6.172299] XXXXXXXXXXX: dwc3_probe 1834 > [ 6.172426] XXXXXXXXXXX: dwc3_core_init_mode 1386 > [ 6.176391] XXXXXXXXXXX: dwc3_drd_init 593 > [ 6.181573] dwc3 dwc3.0.auto: Driver dwc3 requests probe deferral > [ 6.191886] platform dwc3.0.auto: Added to deferred list > [ 6.197249] platform dwc3.0.auto: Retrying from deferred list > [ 6.203057] bus: 'platform': __driver_probe_device: matched device > dwc3.0.auto with driver dwc3 > [ 6.211783] bus: 'platform': really_probe: probing driver dwc3 with > device dwc3.0.auto > [ 6.219935] XXXXXXXXXXX: dwc3_probe 1822 > [ 6.219952] XXXXXXXXXXX: dwc3_core_init 1092 > [ 6.223903] XXXXXXXXXXX: dwc3_core_init 1095 > [ 6.234839] bus: 'ulpi': __driver_probe_device: matched device > dwc3.0.auto.ulpi with driver tusb1210 > [ 6.248335] bus: 'ulpi': really_probe: probing driver tusb1210 with > device dwc3.0.auto.ulpi > [ 6.257039] driver: 'tusb1210': driver_bound: bound to device > 'dwc3.0.auto.ulpi' > [ 6.264501] bus: 'ulpi': really_probe: bound device > dwc3.0.auto.ulpi to driver tusb1210 > [ 6.272553] debugfs: Directory 'dwc3.0.auto' with parent 'ulpi' > already present! > [ 6.279978] XXXXXXXXXXX: dwc3_core_init 1099 > [ 6.279991] XXXXXXXXXXX: dwc3_core_init 1103 > [ 6.345769] tusb1210 dwc3.0.auto.ulpi: error -110 writing val 0x41 > to reg 0x80 > [ 6.357316] XXXXXXXXXXX: dwc3_probe 1834 > [ 6.357447] XXXXXXXXXXX: dwc3_core_init_mode 1386 > [ 6.361402] XXXXXXXXXXX: dwc3_drd_init 593 > [ 6.366589] dwc3 dwc3.0.auto: Driver dwc3 requests probe deferral > [ 6.376901] platform dwc3.0.auto: Added to deferred list > > which renders the system completely unusable, but USB host is > definitely going to be broken too. Now, ironically, with my patch > in-place, an attempt to probe extcon that ends up deferring the probe > happens before the ULPI driver failure (which wasn't failing driver > probe prior to https://lore.kernel.org/all/20220213130524.18748-7-hdegoede@redhat.com/), > there no "driver binding" event that re-triggers deferred probe > causing the loop, so the system progresses to a point where extcon is > available and dwc3 driver eventually loads. > > After that, and I don't know if I'm doing the same test, USB host > seems to work as expected. lsusb works, my USB stick enumerates as > expected. Switching the USB mux to micro-USB and back shuts the host > functionality down and brings it up as expected. Now I didn't try to > load any gadgets to make sure USB gadget works 100%, but since you > were saying it was USB host that was broken, I wasn't concerned with > that. Am I doing the right test? > > For the reference what I test with is: > - vanilla kernel, no patch delta (sans minor debug tracing) + initrd > built with Buildroot 2022.08.1 > - Initrd is using systemd (don't think that really matters, but who knows) > - U-Boot 2022.04 (built with Buildroot as well) > - kernel config is x86_64_defconfig + whatever I gathered from *.cfg > files in https://github.com/edison-fw/meta-intel-edison/tree/master/meta-intel-edison-bsp/recipes-kernel/linux/files
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