On Fri, 2023-09-08 at 08:25 +0300, Ville Syrjala wrote:
From: Ville Syrjälä ville.syrjala@linux.intel.com
Apparently Acer Chromebook C740 (BDW-ULT) doesn't have the eDP HPD line properly connected, and thus fails the new HPD check during eDP probe. The result is that we lose the eDP output.
I suspect all such machines would all be Chromebooks or other
Small duplication here "...all such machines would all...".
Linux exclusive systems as the Windows driver likely wouldn't work either. I did check a few other BDW machines here and those do have eDP HPD connected, one of them even is a different Chromebook (Samus).
To account for these funky machines let's skip the HPD check when it looks like the eDP port is the only one using that specific AUX channel. In case of multiple ports sharing the same AUX CH (eg. on Asrock B250M-HDV) we still do the check and thus should correctly ignore the eDP port in favor of the other DP port (usually a DP->VGA converter).
v2: Don't oops during list iteration
Cc: stable@vger.kernel.org Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9264 Fixes: cfe5bdfb27fa ("drm/i915: Check HPD live state during eDP probe") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
Regardless of the small grammatical issue, LGTM:
Reviewed-by: Luca Coelho luciano.coelho@intel.com
-- Cheers, Luca.