Re: Regarding usb dwc3 core shutdown callback

[Sandeep Maheswaram]

Hi,

On 8/26/2021 4:13 PM, Felipe Balbi wrote:
> Hi,
>
> Sandeep Maheswaram <sanm@xxxxxxxxxxxxxx> writes:
> > > (why isn't this email plain/text? Content Type was set to multipart
> > > alternative, please configure your email client correctly :-)
> > >
> > > While at that, also make sure to break lines at 80-columns)
> > >
> > > Sandeep Maheswaram <sanm@xxxxxxxxxxxxxx> writes:
> > > > Hi,
> > > >
> > > > Earlier I have posted the patch for usb dwc3 core shutdown callback
> > > >
> > > > https://lore.kernel.org/linux-arm-msm/1618380209-20114-1-git-send-email-sanm@xxxxxxxxxxxxxx/
> > > >
> > > > and it was reverted due to issues.
> > > Right, as should be expected when we find regressions
> > >
> > > > https://lore.kernel.org/linux-usb/20210603151742.298243-1-alexandru.elisei@xxxxxxx/
> > > >
> > > > As we already have shutdown callback in xhci plat driver where we halt
> > > > the controller, so there will be no transactions with usb devices.
> > > >
> > > > https://lore.kernel.org/linux-usb/20200306092328.41253-1-ran.wang_1@xxxxxxx/
> > > >
> > > > So I think dwc3 core shutdown may not be required at least when we are
> > > > using host mode. Let me know your opinion about this.
> > > If that's the case, then sure. Please validate the condition, though,
> > > and kindly report back on your findings
> > I have enabled couple of logs in shutdown path and see no URBs
> > enqueued after xhci shut down.
> >
> > Hope this is enough for validation . Please suggest if anything more I
> > could do.
> how about writing a little script to kexec into another kernel for a few
> hundred iterations and make sure things still work after all that?

Currently kexec is not supported on qcom devices.  Anything we can do 
apart from kexec?