On Fri, Oct 7, 2022 at 6:07 AM Ferry Toth <fntoth@xxxxxxxxx> 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? 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@xxxxxxxxxx/), 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
