2020-06-16 09:05:42

by Jisheng Zhang

Subject: [Query]usb: dwc2: suspend/resume support for DWC2_POWER_DOWN_PARAM_NONE case

Hi,

After reading current dwc2 code, I got an impression that resume from suspend
to ram isn't supported for DWC2_POWER_DOWN_PARAM_NONE case, right? In fact
we do see usb device can't resume properly with DWC2_POWER_DOWN_PARAM_NONE case.

If the impression is true, what's the proper technical direction? Add
dwc2_host_enter_suspend() as dwc2_host_enter_hibernation()
and
dwc2_host_exit_suspend() as dwc2_host_exit_hibernation()?

Thanks in advance,
Jisheng

2020-06-16 13:55:57

by Minas Harutyunyan

Subject: Re: [Query]usb: dwc2: suspend/resume support for DWC2_POWER_DOWN_PARAM_NONE case

Hi Jisheng,

On 6/16/2020 1:03 PM, Jisheng Zhang wrote:
> Hi,
>
> After reading current dwc2 code, I got an impression that resume from suspend
> to ram isn't supported for DWC2_POWER_DOWN_PARAM_NONE case, right? In fact
'ram' Do you mean on suspend save registers in RAM?
If yes, then in case when power_down is _NONE then no any register
saving/restoring to/from RAM should be performing.
> we do see usb device can't resume properly with DWC2_POWER_DOWN_PARAM_NONE case.
>
If you see any issue on resume in mentioned case then more probably is
some another issue which can debugged.

> If the impression is true, what's the proper technical direction? Add
> dwc2_host_enter_suspend() as dwc2_host_enter_hibernation()
> and
> dwc2_host_exit_suspend() as dwc2_host_exit_hibernation()?
>
> Thanks in advance,
> Jisheng
>
Thanks,
Minas