Re: [PATCH] usb: typec: ucsi: Handle incorrect num_connectors capability

[Heikki Krogerus]

On Thu, Sep 18, 2025 at 09:50:30AM +0200, Greg KH wrote:
> On Wed, Sep 17, 2025 at 02:14:28PM -0400, Mark Pearson wrote:
> > Hi all,
> > 
> > On Fri, Aug 22, 2025, at 8:54 AM, Mark Pearson wrote:
> > > Hi Greg,
> > >
> > > On Fri, Aug 22, 2025, at 12:51 AM, Greg KH wrote:
> > >> On Thu, Aug 21, 2025 at 02:53:07PM -0400, Mark Pearson wrote:
> > >>> The UCSI spec states that the num_connectors field is 7 bits, and the
> > >>> 8th bit is reserved and should be set to zero.
> > >>> Some buggy FW has been known to set this bit, and it can lead to a
> > >>> system not booting.
> > >>> Flag that the FW is not behaving correctly, and auto-fix the value
> > >>> so that the system boots correctly.
> > >>> 
> > >>> Found on Lenovo P1 G8 during Linux enablement program. The FW will
> > >>> be fixed, but seemed worth addressing in case it hit platforms that
> > >>> aren't officially Linux supported.
> > >>> 
> > >>> Signed-off-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
> > >>
> > >> Any hints as to what commit id this fixes?
> > >>
> > >> thanks,
> > >>
> > >> greg k-h
> > >
> > > Maybe 3cf657f ('Remove all bit-fields')?
> > >
> > > The commit there states that 'We can't use bit fields with data that is 
> > > received or send
> > > to/from the device.'
> > > Not sure why that is, but I assumed this means we shouldn't change the 
> > > structure to use 7 bits for num_connectors, which was my original plan.
> > >
> > > After that, we go all the way back to the file creation (c1b0bc2) where 
> > > it was defined as 8 bit.
> > >
> > 
> > Just a gentle nudge to see if there are any concerns or questions with the patch.
> 
> I was waiting for the maintainer of this code to review it :)

So not Fixes tag?

Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

-- 
heikki