[PATCH 02/10] usb: dwc3: core: improve reset sequence

[Marek Vasut]

On 6/22/23 12:00, Eugen Hristev wrote:
> On 6/22/23 12:58, Eugen Hristev wrote:
>> From: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
>>
>> [ Felipe: Ported from Linux kernel commit
>>       f59dcab17629 ("usb: dwc3: core: improve reset sequence") ]
>>
>> According to Synopsys Databook, we shouldn't be relying on
>> GCTL.CORESOFTRESET bit as that's only for debugging purposes.
>> Instead, let's use DCTL.CSFTRST if we're OTG or PERIPHERAL mode.
>>
>> Host side block will be reset by XHCI driver if necessary. Note that this
>> reduces amount of time spent on dwc3_probe() by a long margin.
>>
>> We're still gonna wait for reset to finish for a long time
>> (default to 1ms max), but tests show that the reset polling loop executed
>> at most 19 times (modprobe dwc3 && modprobe -r dwc3 executed 1000
>> times in a row).
>>
>> Without proper core reset, observing random issues like when the
>> USB(DWC3) is in device mode, the host device is not able to detect the
>> USB device.
>>
>> Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
>> [eugen.hristev at collabora.com: keep the PHY resets code]
>> Signed-off-by: Eugen Hristev <eugen.hristev at collabora.com>
>> ---
>>
>> Just resending for consistency with my series. I readded the PHY resets
>> code because it breaks my PHYs if it's being removed
>>
>> Marek, I know you NAKed this, that's fine, I am simply adding this patch
>> (and the others here) for consistency
> 
>  >>>
>  >>> Please sync the DWC3 patchset with Linux first, else this is a NAK.
>  >>>
>  >>> Please do not make the DWC3 driver an unmaintainable mess.
>  >>>
>  >>> I already explained this to AMD/Xilinx, multiple times, they 
> ignored all my requests without even trying, so my NAK still stands.
>  >>>
>  >>> The sync should be easy and mechanical.
>  >>>
>  >>> Please do not try to sneak those patches in as part of another series.
>  >>
>  >> Hi Marek,
>  >>
>  >> I know, I saw the discussion. I am adding the patch in case someone 
> wants to use it. Definitely I am not trying to sneak anything. Read the 
> cover letter as well if you have doubts.
>  >
>  > I tried asking intel just now to fix what AMD couldn't, so let's see.
> 
> I will try to do it myself, if I have some spare time in the following 
> months, if nobody does it.
> 
> ^^
> I am resending the conversation above as I forgot to CC the mailing list 
> on the initial thread

I appreciate it. It really should be easy to do.