Re: [PATCH v2 2/2] Revert "usb: dwc3: Don't switch OTG -> peripheral if extcon is present"
From: Ferry Toth
Date: Wed Oct 12 2022 - 05:30:30 EST
Hi
On 11-10-2022 22:50, Andrey Smirnov wrote:
On Tue, Oct 11, 2022 at 11:54 AM Ferry Toth <fntoth@xxxxxxxxx> wrote:
Hi,
Op 10-10-2022 om 23:35 schreef Andrey Smirnov:
On Mon, Oct 10, 2022 at 1:52 PM Ferry Toth <fntoth@xxxxxxxxx> wrote:
Hi
Op 10-10-2022 om 13:04 schreef Ferry Toth:
Hi
On 10-10-2022 07:02, Andrey Smirnov wrote:
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?
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
Updated Yocto recipe for v6.0 here:
https://github.com/htot/meta-intel-edison/blob/honister/meta-intel-edison-bsp/recipes-kernel/linux/linux-yocto_6.0.bb
#75-#77 are the 2 reverts from Andy, + one SOF revert (not related to
this thread).
Please drop all of this
https://github.com/htot/meta-intel-edison/blob/honister/meta-intel-edison-bsp/recipes-kernel/linux/linux-yocto_6.0.bb#L69-L77
and re do the testing. Assuming things are still broken, that's how
you want to do the bisecting.
I removed 4 patches:
0043b-TODO-driver-core-Break-infinite-loop-when-deferred-p.patch
0044-REVERTME-usb-dwc3-gadget-skip-endpoints-ep-18-in-out.patch
0001-Revert-USB-fixup-for-merge-issue-with-usb-dwc3-Don-t.patch
0001-Revert-usb-dwc3-Don-t-switch-OTG-peripheral-if-extco.patch
Please remove all custom patches so we are on the same page. I don't
suspect the 8250 related changes to affect anything, but I also would
like to be testing the same thing. I'm testing vanilla v6.0
Alright, but don't expect any change. The 8250 patches are related to
using DMA for the serial ports (except the console). It may affect
bluetooth, the serial port on the arduino connector, but not the console.
and indeed as you expect kernel boots (no infinite loop). However dwc3
host mode is not working as in your case, device mode works fine (Yocto
configures a set of gadgets for me).
What do you do to test host mode working? lsusb? Something else?
Asking to make sure I'm doing something equivalent on my end.
I have a smsc95xx 4p usb hub with 1 eth port continuously plugged. It
has leds on all ports so when it works it lights up like a Christmas tree.
But I also tried plugging a usb stick.
It maybe that lsusb is not enough. Iirc the root hub is there, but the
tusb1210 not and then device plugs are not detected. So in my case none
of the leds on the hub turn on.
Just to be sure if I could have bisected without 0043a I added back the
2 0001-Revert* and indeed I run into the infinite loop with the console
spitting out continuous:
debugfs: Directory 'dwc3.0.auto' with parent 'ulpi' already present!
tusb1210 dwc3.0.auto.ulpi: error -110 writing val 0x41 to reg 0x80
so yes it seems either 0043b or your patch "usb: dwc3: Don't switch OTG
-> peripheral if extcon is present" is needed to boot (break the
infinite loop). But your patch is in my case not sufficient to make host
mode work.
Next step would be to establish if USB is working before my patch. You
should be able to avoid the boot loop if you disable the
"phy-tusb1210" driver. The driver fails to probe anyway, so it's not
very likely to be crucial for functioning, so it should allow you to
try things with my patch reverted:
You lost me here. With "boot loop" you mean "probe loop" right? Why do
you think the tusb1210 driver is not crucial?
See "phy: ti: tusb1210: Don't check for write errors when powering on"
It should not be failing to probe (and with Andy's "Break-infinite-loop"
patch is doesn't) as without the tusb1210 usb host mode won't work as
device plugs are not detected.
Earlier in this thread we had:
"The effect of the patch is that on Merrifield (I tested with Intel
Edison Arduino board which has a HW switch to select between host and
device mode) device mode works but in host mode USB is completely not
working.
Currently on host mode - when working - superfluous error messages from
tusb1210 appear. When host mode is not working there are no tusb1210
messages in the logs / on the console at all. Seemingly tusb1210 is not
probed, which points in the direction of a relation to extcon."
git revert 8bd6b8c4b100 0f0101719138
After that, if things start working, it'd make sense to re-do your
function re-arranging experiment to re-validate it.
As I understand it depends a bit on the timing, I might have a different
initrd (built by Yocto vs. Buildroot). F.i. I see I have
extcon-intel-mrfld in initrd and dwc3 / phy-tusb1210 built-in.
You mentioned that your rootfs image does some gadget configuration
for you. Can this be disabled? If yes, it'd make sense to check if
this could be a variable explaining the difference.
This is done through configfs only when the switch is set to device mode.
What U-Boot version are you running? AFACT U-Boot will touch that
particular IP block, so this might be somewhat relevant.
IIRC if have v2022.04 but tested v2021.10 earlier (no difference).