Re: BUG with linux 5.9.0 with dwc3 in gadget mode

From: Ferry Toth <fntoth@gmail.com>
To: Felipe Balbi <balbi@kernel.org>,
	Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Jack Pham <jackp@codeaurora.org>
Subject: Re: BUG with linux 5.9.0 with dwc3 in gadget mode
Date: Thu, 5 Nov 2020 22:29:24 +0100	[thread overview]
Message-ID: <ec15a515-6dbc-1224-a457-d5ac4a4db280@gmail.com> (raw)
In-Reply-To: <871rhin1yt.fsf@kernel.org>

Hi,

Op 28-10-2020 om 10:18 schreef Felipe Balbi:
> Hi,
>
> Ferry Toth <fntoth@gmail.com> writes:
>> Op 27-10-2020 om 22:16 schreef Andy Shevchenko:
>>> On Tue, Oct 27, 2020 at 10:13 PM Ferry Toth <fntoth@gmail.com> wrote:
>>>> Op 22-10-2020 om 15:43 schreef Andy Shevchenko:
>>>>> On Thu, Oct 22, 2020 at 4:21 PM Thinh Nguyen <Thinh.Nguyen@synopsys.com> wrote:
>>>>>> Ferry Toth wrote:
>>> ...
>>>
>>>>>> There are some fixes to dwc3 in kernel mainline. Is it possible to test
>>>>>> this against linux-next?
>>>>> I think the best is to wait for v5.10-rc1 and retest.
>>> Can you give a try of v5.10-rc1?
>> Yes, I just tried:
>>
>> I booted in host mode, then flip the switch. Gadget come up, go down
>> once, then come up again and stay up.
> please collect trace events. It's important to figure out why it's going
> down, even if only once. Make sure to collect trace *and* dmesg so we
> can correlate trace with the reenumeration that should show up in dmesg.
>
> thanks

Sorry, I had to replace mobo. Now back on this.

As is, on Edison I can record with something like "perf record -e 
'dwc3:dwc3_gadget*' -e 'gadget:*' -g -a".
Then get the trace buffer with "perf script > gadget.txt". Then at each 
trace point we get a stack trace like:

file-storage   831 [001]  4445.240038: dwc3:dwc3_gadget_ep_cmd: [FAILED 
TO PARSE] name=ep4in cmd=524295 param0=0 param1=0 param2=0 cmd_status=0
     ffffffff9a35b7e7 __traceiter_dwc3_gadget_ep_cmd+0x37 
([kernel.kallsyms])
     ffffffff9a35b7e7 __traceiter_dwc3_gadget_ep_cmd+0x37 
([kernel.kallsyms])
     ffffffff9a35fa40 dwc3_send_gadget_ep_cmd+0x320 ([kernel.kallsyms])
     ffffffff9a3606d0 __dwc3_gadget_kick_transfer+0x200 ([kernel.kallsyms])
     ffffffff9a361114 dwc3_gadget_ep_queue+0xe4 ([kernel.kallsyms])
     ffffffff9a3afc3a usb_ep_queue+0x2a ([kernel.kallsyms])
     ffffffffc047c301 start_transfer.isra.0+0x21 ([kernel.kallsyms])
     ffffffffc047c88a start_in_transfer.isra.0+0x3a ([kernel.kallsyms])
     ffffffffc047c93d send_status+0x8d ([kernel.kallsyms])
     ffffffffc047dd05 fsg_main_thread+0x3c5 ([kernel.kallsyms])
     ffffffff99c853b9 kthread+0xf9 ([kernel.kallsyms])
     ffffffff99c01a32 ret_from_fork+0x22 ([kernel.kallsyms])

"perf list" shows the tracepoint events, the same as under 
/sys/kernel/debug/tracing/events/

Question is which points to trace (above command fills buffer to 35MB in 
10sec). Do you have suggestions?

Thanks