Re: [PATCH RFC 2/2] usb: typec: ucsi: increase timeout for PPM reset operations

Greg Kroah-Hartman
2025-02-17T10:32:45Z

On Mon, Feb 17, 2025 at 01:18:25PM +0300, Fedor Pchelkin wrote:
> On Thu, 13. Feb 15:58, Heikki Krogerus wrote:
> > On Thu, Feb 06, 2025 at 09:43:15PM +0300, Fedor Pchelkin wrote:
> > > It is observed that on some systems an initial PPM reset during the boot
> > > phase can trigger a timeout:
> > >
> > > [ 6.482546] ucsi_acpi USBC000:00: failed to reset PPM!
> > > [ 6.482551] ucsi_acpi USBC000:00: error -ETIMEDOUT: PPM init failed
> > >
> > > Still, increasing the timeout value, albeit being the most straightforward
> > > solution, eliminates the problem: the initial PPM reset may take up to
> > > ~8000-10000ms on some Lenovo laptops. When it is reset after the above
> > > period of time (or even if ucsi_reset_ppm() is not called overall), UCSI
> > > works as expected.
> > >
> > > Moreover, if the ucsi_acpi module is loaded/unloaded manually after the
> > > system has booted, reading the CCI values and resetting the PPM works
> > > perfectly, without any timeout. Thus it's only a boot-time issue.
> > >
> > > The reason for this behavior is not clear but it may be the consequence
> > > of some tricks that the firmware performs or be an actual firmware bug.
> > > As a workaround, increase the timeout to avoid failing the UCSI
> > > initialization prematurely.
> > >
> > > Fixes: b1b59e16075f ("usb: typec: ucsi: Increase command completion timeout value")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Fedor Pchelkin <boddah8794@gmail.com>
> >
> > Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>
> Thanks for review!
>
> Should I respin the series or it can be taken as is despite being
> initially tagged an RFC material?

For obvious reasons, I can't take RFC patches as obviously you didn't
think they were worthy of being taken, hence you marking them that way
:)

thanks,

greg k-h