Re: USB DWC2 stops responding when insert/remove cable multiple times

[Minas Harutyunyan <Minas.Harutyunyan-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>]

Hi Otavio,

On 2/21/2020 6:07 PM, Otavio Salvador wrote:
> On Fri, Feb 21, 2020 at 11:06 AM Otavio Salvador
> <otavio@ossystems.com.br> wrote:
>> On Fri, Feb 21, 2020 at 3:52 AM Minas Harutyunyan
>> <Minas.Harutyunyan@synopsys.com> wrote:
>>> On 2/20/2020 5:16 PM, Otavio Salvador wrote:
>>>> Hello Minas,
>>>>
>>>> Thanks for all your help on this, ...
>>>>
>>>> On Thu, Feb 20, 2020 at 3:59 AM Minas Harutyunyan
>>>> <Minas.Harutyunyan@synopsys.com> wrote:
>>>>>
>>>>> On 2/19/2020 7:10 PM, Otavio Salvador wrote:
>>>> ...
>>>>>> What sequence do you want us to do?
>>>>>
>>> Please provide dwc2 debug log when stop working with g_serial exception
>>> dump inside.
>>> Also provide dwc2 log when it's work without issue.
>>
>> Attached.
> 
Reviewed all logs. Not found any dwc2 related issue. Not able to 
reproduce on my setup. My log on rmmod g_serial:

[68784.817773] g_serial gadget: reset config
[68784.817775] g_serial gadget: acm ttyGS0 deactivated
[68784.817779] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable(ep 000000005e9ae420)
[68784.817784] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable: DxEPCTL=0x08080200
[68784.817791] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable(ep 00000000e6730f2b)
[68784.817796] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable: DxEPCTL=0x08880200
[68784.817805] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable(ep 00000000cef05e9b)
[68784.817809] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable: DxEPCTL=0x084c000a
[68784.817820] g_serial gadget: acm ttyGS0 deactivated
[68784.817894] usb 5-4: USB disconnect, device number 6
[68784.817975] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable(ep 00000000e6730f2b)
[68784.817980] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable: DxEPCTL=0x088a0200

Pay attention g_serial twice performing ttySG0 deactivation.
In my setup second deactivation passed Ok, but in your case exception 
back trace print out with NULL pointer de-reference on spin_lock_irq. 
Could you please add debug print before spin_lock_irq() in function 
gs_close() in file u_serial.c to check tty, tty->driver_data. Are these 
vars NULL or no.
Just rmmod g_serial case fully enough.

Thanks,
Minas

> Forgot to attach the files.
>