Re: usb: dwc2: USB on Agilex platform broken after commit 50fb0c128b6e

[Dinh Nguyen <dinguyen@kernel.org>]

On 12/14/21 12:13 AM, Minas Harutyunyan wrote:
> Hi Dinh,
> 
> On 12/14/2021 12:40 AM, Dinh Nguyen wrote:
>>
>>
>> On 12/13/21 10:13 AM, Dinh Nguyen wrote:
>>> Hi Minas,
>>>
>>> Thanks for replying!
>>>
>>> On 12/13/21 3:47 AM, Minas Harutyunyan wrote:
>>>> Hi Dinh,
>>>>
>>>> On 12/9/2021 1:44 AM, Dinh Nguyen wrote:
>>>>> Hi Arthur,
>>>>>
>>>>> The usb driver is getting this error:
>>>>>
>>>>> [    1.539856] Hardware name: SoCFPGA Agilex SoCDK (DT)
>>>>> [    1.544799] Call trace:
>>>>> [    1.547233]  dump_backtrace+0x0/0x1c0
>>>>> [    1.550897]  show_stack+0x18/0x68
>>>>> [    1.554202]  dump_stack+0xd8/0x134
>>>>> [    1.557597]  __report_bad_irq+0x38/0xf0
>>>>> [    1.561423]  note_interrupt+0x31c/0x3e8
>>>>> [    1.565244]  handle_irq_event_percpu+0x60/0x90
>>>>> [    1.569671]  handle_irq_event+0x48/0xe0
>>>>> [    1.573491]  handle_fasteoi_irq+0xb0/0x138
>>>>> [    1.577574]  generic_handle_irq+0x30/0x48
>>>>> [    1.581567]  __handle_domain_irq+0x60/0xb8
>>>>> [    1.585646]  gic_handle_irq+0xb4/0xd0
>>>>> [    1.589300]  el1_irq+0xb8/0x150
>>>>> [    1.592428]  arch_cpu_idle+0x18/0x28
>>>>> [    1.595992]  default_idle_call+0x24/0x5c
>>>>> [    1.599899]  do_idle+0x1f4/0x290
>>>>> [    1.603118]  cpu_startup_entry+0x28/0x68
>>>>> [    1.607026]  rest_init+0xd8/0xe8
>>>>> [    1.610242]  arch_call_rest_init+0x10/0x1c
>>>>> [    1.614329]  start_kernel+0x50c/0x544
>>>>> [    1.617980] handlers:
>>>>> [    1.620241] [<00000000ae601aac>] dwc2_handle_common_intr
>>>>> [    1.625541] [<00000000255d793a>] dwc2_hsotg_irq
>>>>> [    1.630056] [<000000000bc68ab4>] usb_hcd_irq
>>>>> [    1.634312] Disabling IRQ #33
>>>>>
>>>>> After a git-bisect, the result is this commit:
>>>>>
>>>>>
>>>>> commit 50fb0c128b6e8df62200ba85c05ecd6b1396476d
>>>>> Author: Artur Petrosyan<Arthur.Petrosyan@synopsys.com>
>>>>> Date:   Tue Apr 13 11:37:15 2021 +0400
>>>>>
>>>>>        usb: dwc2: Add clock gating entering flow by system suspend
>>>>>        If not hibernation nor partial power down are supported,
>>>>>        clock gating is used to save power.
>>>>>        Adds a new flow of entering clock gating when PC is
>>>>>        suspended.
>>>>>        Signed-off-by: Artur Petrosyan<Arthur.Petrosyan@synopsys.com>
>>>>> Link:https://urldefense.com/v3/__https://lore.kernel.org/r/20210413073716.30C13A0094@mailhost.synopsys.com__;!!A4F2R9G_pg!IjGS70cMXB9miMnPdcoGriUpDvARm7ScwrlQXAiH9qN-ZnpcaiM_gD-KWp___MVyvEPm_djJ$
>>>>>
>>>>>        Signed-off-by: Greg Kroah-Hartman<gregkh@linuxfoundation.org>
>>>>>
>>>>> The DWC2 USB version on the Agilex platform is
>>>>> 0x4F54330A
>>>>>
>>>> Could you please provide HW configuration registers values (GHWCFG1-4).
>>>>
>>>
>>> [    0.987779] dwc2 ffb00000.usb: GHWCFG1    @0xFFFF800012940044 :
>>> 0x00000000
>>> [    0.994644] dwc2 ffb00000.usb: GHWCFG2    @0xFFFF800012940048 :
>>> 0x238FFC90
>>> [    1.001498] dwc2 ffb00000.usb: GHWCFG3    @0xFFFF80001294004C :
>>> 0x1F8002E8
>>> [    1.008350] dwc2 ffb00000.usb: GHWCFG4    @0xFFFF800012940050 :
>>> 0xFE0F0020
>>>
>>>
>>> I did a little debugging, and noticed that the GINTSTS_PRTINT is
>>> firing, so the dwc2_handle_common_intr() is getting called
>>> continuously. There's doesn't seem to be way to handle the
>>> GINTSTS_PRTINT bit, because there's a check for device_mode().
>>>
>>
>> It looks like the LPMMode bit is disabled in the GHWCFG3. Could that be
>> the reason why?
>>
>> Dinh
> 
> Could you please disable clock gating by adding to
> dwc2_set_default_params() function follow line:
> p->no_clock_gating = true;
> like in dwc2_set_s3c6400_params() function.
> 

That did not fix the issue. However, if I remove the line:

+               /* After entering suspend, hardware is not accessible */
+               clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

Then the issue gets fixed.

Dinh