Re: [REGRESSION] Re: ELAN1206 Touchpad Bugzilla 219799

From: Andy Shevchenko
Date: Tue Jun 03 2025 - 04:34:39 EST


On Mon, Jun 02, 2025 at 11:37:21PM +0530, Aditya Garg wrote:
> On 02-06-2025 11:35 pm, Aditya Garg wrote:
> > On 28-05-2025 07:44 pm, agski33 wrote:

...

> >> I am currently experiencing the issue that was previously reported in the
> >> following BugZilla
> >> entry: https://bugzilla.kernel.org/show_bug.cgi?id=219799. ; I noticed that
> >> the bug was marked as NEEDINFO so I attempted to fill in the relevant
> >> information.
> >>
> >>  From my testing, it seems like IDMA transfers relating to the touchpad
> >> input are taking too long and causing timeouts within hid-multitouch.  

Is touchpad interface is I²C?

> >> I contacted ASUS in an attempt to obtain information relating to the
> >> workings of the touchpad that may assist with this issue, however I
> >> believe it is unlikely that I will be able to obtain anything useful from
> >> them.
> >>
> >> I am wondering if anyone has any additional suggestions for next debugging
> >> steps or things that I may try - would be happy to provide any additional
> >> information or do additional debugging etc.
> >>
> >> System Details:
> >> Device: ASUS Q528EH with ELAN1206 Touchpad
> >> Kernel versions: 6.9-rc6 is where the issue starts, persists through all
> >> kernel versions after including latest.
> >> Symptoms: Touchpad cursor will not move.  
> >>  Additional Observations: Something of potential interest that I noticed
> >> was that it appeared the touchpad is sending data byte by byte when doing
> >> an IDMA transfer, not sure if that is normal or not.
> >>
> >> Any suggestions for next steps are appreciated!  Thank you in advance for your time and input.
> >
> > Looking at https://bugzilla.kernel.org/show_bug.cgi?id=219799#c2, dd4478d63b6a2b6891fcc1800eb26ce3f1ead1d4
> > seems to be the patch causing regression.
>
> My bad, its 9140ce47872bfd89fca888c2f992faa51d20c2bc, the mailing list link is correct though.

It doesn't matter, the patch is technically correct — we do not serve the
spurious (not ours) interrupts.

> > https://lore.kernel.org/lkml/20240321120453.1360138-1-andriy.shevchenko@xxxxxxxxxxxxxxx/
> >
> > Ccing relevant folks here.

--
With Best Regards,
Andy Shevchenko