Re: mhi resume failure on reboot with 6.13-rc2

[Johan Hovold <johan@kernel.org>]

On Mon, Dec 16, 2024 at 05:25:23PM +0100, Loic Poulain wrote:
> On Mon, 16 Dec 2024 at 15:13, Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org> wrote:
> > On Mon, Dec 16, 2024 at 02:20:09PM +0100, Johan Hovold wrote:
> > > On Mon, Dec 16, 2024 at 01:10:21PM +0530, Manivannan Sadhasivam wrote:
> > > > On Wed, Dec 11, 2024 at 04:03:59PM +0100, Johan Hovold wrote:
> > > > > On Wed, Dec 11, 2024 at 08:23:15PM +0530, Manivannan Sadhasivam wrote:
> > > > > > On Wed, Dec 11, 2024 at 03:17:22PM +0100, Johan Hovold wrote:
> > > > >
> > > > > > > I just hit the following modem related error on reboot of the x1e80100
> > > > > > > CRD for the second time with 6.13-rc2:
> > > > > > >
> > > > > > >       [  138.348724] shutdown[1]: Rebooting.
> > > > > > >         [  138.545683] arm-smmu 3da0000.iommu: disabling translation
> > > > > > >         [  138.582505] mhi mhi0: Resuming from non M3 state (SYS ERROR)
> > > > > > >         [  138.588516] mhi-pci-generic 0005:01:00.0: failed to resume device: -22
> > > > > > >         [  138.595375] mhi-pci-generic 0005:01:00.0: device recovery started
> > > > > > >         [  138.603841] wwan wwan0: port wwan0qcdm0 disconnected
> > > > > > >         [  138.609508] wwan wwan0: port wwan0mbim0 disconnected
> > > > > > >         [  138.615137] wwan wwan0: port wwan0qmi0 disconnected
> > > > > > >         [  138.702604] mhi mhi0: Requested to power ON
> > > > > > >         [  139.027494] mhi mhi0: Power on setup success
> > > > > > >         [  139.027640] mhi mhi0: Wait for device to enter SBL or Mission mode
> > > > > > >
> > > > > > > and then the machine hangs.

> > > I've only hit this issue three times and only since 6.13-rc2. So not
> > > sure how useful that sort of experiment would be.

> > I'm not sure where exactly it got stuck. I've asked Qcom folks to reproduce this
> > issue. We will investigate and hopefully get back with a fix asap.
> >
> > > This is with the SDX65 modem in the x1e80100 CRD:
> > >
> > >       17cb:0308
> 
> I have another MHI modem model, but will try to reproduce during the
> week, any idea on the bug rate?

I've now hit this four times. And only since rc2. So I guess that's
something like four times in a hundred reboots or so.

I added some printks to the pci_generic driver this morning and have
been running a boot loop for one hundred iterations without hitting the
issue even once, however. Perhaps the printks alters the timing enough
to avoid the fw crash or race.

Johan