Re: [PATCH v4 3/9] usb: dwc3: Increase timeout for CmdAct cleared by device controller

[John Stultz]

On Wed, May 6, 2020 at 2:00 AM Jun Li <lijun.kernel@xxxxxxxxx> wrote:
> John Stultz <john.stultz@xxxxxxxxxx> ä2019å10æ30æåä äå5:18åéï
> > On Tue, Oct 29, 2019 at 2:11 AM Felipe Balbi <balbi@xxxxxxxxxx> wrote:
> > > John Stultz <john.stultz@xxxxxxxxxx> writes:
> > > > From: Yu Chen <chenyu56@xxxxxxxxxx>
> > > >
> > > > It needs more time for the device controller to clear the CmdAct of
> > > > DEPCMD on Hisilicon Kirin Soc.
> > >
> > > Why does it need more time? Why is it so that no other platform needs
> > > more time, only this one? And which command, specifically, causes
> > > problem?
>
> Sorry for my back to this so late.
>
> This change is required on my dwc3 based HW too, I gave a check
> and the reason is suspend_clk is used in case the PIPE phy is at P3,
> this slow clock makes my EP command below timeout.
>
> dwc3_gadget_ep_cmd: ep0out: cmd 'Set Endpoint Configuration' [401]
> params 00001000 00000500 00000000 --> status: Timed Out
>
> Success case takes about 400us to complete, see below trace(44.286278
> - 44.285897 = 0.000381):
>
> configfs_acm.sh-822   [000] d..1    44.285896: dwc3_writel: addr
> 000000006d59aae1 value 00000401
> configfs_acm.sh-822   [000] d..1    44.285897: dwc3_readl: addr
> 000000006d59aae1 value 00000401
> ... ...
> configfs_acm.sh-822   [000] d..1    44.286278: dwc3_readl: addr
> 000000006d59aae1 value 00000001
> configfs_acm.sh-822   [000] d..1    44.286279: dwc3_gadget_ep_cmd:
> ep0out: cmd 'Set Endpoint Configuration' [401] params 00001000
> 00000500 00000000 --> status: Successful
>
> Hi John,
>
> Do you still have this problem? if yes, What's the value of
> USBLNKST[21:18] when the timeout happens?

Sorry. As I mentioned, I was working to upstream a patchset that I
hadn't created, so the context I had was limited. As I couldn't
reproduce an issue without the change on the device I had, I figured
it would be best to drop it.

However, as you have some analysis and rational for why such a change
would be needed, I don't have an objection to it. Do you want to
resubmit the patch with your explanation and detailed log above in the
commit message?

thanks
-john