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

[Dinh Nguyen <dinguyen@kernel.org>]

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://lore.kernel.org/r/20210413073716.30C13A0094@mailhost.synopsys.com
>>       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().

Dinh