Re: [PATCH v2] bus: mhi: core: Add support for forced PM resume

[Manivannan Sadhasivam]

On Thu, Dec 09, 2021 at 04:35:25PM +0200, Kalle Valo wrote:
> Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> writes:
> 
> > From: Loic Poulain <loic.poulain@xxxxxxxxxx>
> >
> > For whatever reason, some devices like QCA6390, WCN6855 using ath11k
> > are not in M3 state during PM resume, but still functional. The
> > mhi_pm_resume should then not fail in those cases, and let the higher
> > level device specific stack continue resuming process.
> >
> > Add an API mhi_pm_resume_force(), to force resuming irrespective of the
> > current MHI state. This fixes a regression with non functional ath11k WiFi
> > after suspend/resume cycle on some machines.
> >
> > Bug report: https://bugzilla.kernel.org/show_bug.cgi?id=214179
> >
> > Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
> > Cc: stable@xxxxxxxxxxxxxxx #5.13
> > Link: https://lore.kernel.org/regressions/871r5p0x2u.fsf@xxxxxxxxxxxxxx/
> > Reported-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
> > Reported-by: Pengyu Ma <mapengyu@xxxxxxxxx>
> > Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
> > [mani: Switched to API, added bug report, reported-by tags and CCed stable]
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> >
> > Changes in v2:
> >
> > * Switched to a new API "mhi_pm_resume_force()" instead of the "force" flag as
> >   suggested by Greg. The "force" flag is now used inside the API.
> >
> > Greg: I'm sending this patch directly to you so that you can apply it to
> > char-misc once we get an ACK from Kalle.
> 
> Thanks! I now tested this patch on top v5.16-rc4 using QCA6390 and
> firmware WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1, no issues found:
> 
> Tested-by: Kalle Valo <kvalo@xxxxxxxxxx>
> 
> I'm not expecting any conflicts with ath11k, so please take this via
> Greg's tree. It would be really good to get this regression fixed in
> v5.16, so is it possible to send this to -rc releases?
> 
> For the ath11k part:
> 
> Acked-by: Kalle Valo <kvalo@xxxxxxxxxx>

Thanks. If this patch looks good to Greg, then it will be queued for the next
-rc release.

Thanks,
Mani

> 
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