Re: Dell Inspiron 5558/0VNM2T hangs at resume from suspend when USB 3 is enabled

[Diego Viola]

On Mon, Mar 20, 2017 at 3:27 PM, Diego Viola <diego.viola@xxxxxxxxx> wrote:
> On Mon, Mar 20, 2017 at 1:32 PM, Mathias Nyman
> <mathias.nyman@xxxxxxxxxxxxxxx> wrote:
>> On 20.03.2017 17:39, Diego Viola wrote:
>>>
>>> On Mon, Mar 20, 2017 at 11:21 AM, Mathias Nyman
>>> <mathias.nyman@xxxxxxxxxxxxxxx> wrote:
>>>>
>>>> On 19.03.2017 23:29, Diego Viola wrote:
>>>>>
>>>>>
>>
>>>>>> Still a problem with 4.11.0-rc2-ARCH+
>>>>
>>>> 4.11-rc2 has better xhci tracing, it shows each URB enqueue and dequeue
>>>> and
>>>> giveback.
>>>>
>>>> Could you try enabling xhci tracing before suspending (not the same as
>>>> xhci
>>>> verbose dynamic debug)
>>>> It will generate a lot of data, so better to remove all extra USB
>>>> devices.
>>>>
>>>> xhci tracing can be added with:
>>>>
>>>> mount -t debugfs none /sys/kernel/debug
>>>> echo xhci-hcd >> /sys/kernel/debug/tracing/set_event
>>>>
>>>> and then send the output of cat /sys/kernel/debug/tracing/trace
>>>
>>>
>>> https://bugzilla.kernel.org/attachment.cgi?id=255367
>>>
>>> This is with Linux 4.11.0-rc3-ARCH.
>>>
>>> USB mouse/keyboard was unplugged before booting the machine.
>>>
>>> I didn't do a suspend/resume before getting this trace, should I do that?
>>>
>>> Should I reproduce the hang and get a netconsole dmesg capture with
>>> tracing enabled?
>>
>>
>> A trace and a dmesg of the same  suspend/reusume hang would be great.
>
> I can capture the dmesg with netconsole once the machine hangs, but
> I'm not sure how I could capture /sys/kernel/debug/tracing/trace after
> the hang. I'm unable to use ssh after the hang.
>
>> And if you can then one of a succesful suspend/resume for reference.
>
> Here's the trace after a successful suspend/resume:
>
> https://bugzilla.kernel.org/attachment.cgi?id=255369
>
>>
>> (I haven't yet checked the one you added to bugzilla)
>>
>> -Mathias
>
> Diego

ftrace_dump_on_oops is what I was looking for.

Diego