drm/i915/quirks: Limit eDP rate to HBR2 on HP Pavilion Plus 14-ew1

The eDP panel on the HP Pavilion Plus Laptop 14-ew1xxx advertises HBR3
while leaving the TPS4 support bit clear. The output however flickers, once
link is trained with HBR3.

Until commit 8c9006283e ("Revert "drm/i915/dp: Reject HBR3 when sink
doesn't support TPS4"") such sinks were capped at HBR2 by the TPS4 check
which incidentally kept this panel stable. That check was reverted because
other panels legitimately need HBR3 without advertising TPS4, and the
per-machine QUIRK_EDP_LIMIT_RATE_HBR2 was introduced to handle the affected
machines instead.

Add the machine to the list of devices that need the
QUIRK_EDP_LIMIT_RATE_HBR2.

Fixes: 8c9006283e ("Revert "drm/i915/dp: Reject HBR3 when sink doesn't support TPS4"")
Reported-by: Annoy Cc <annoycc@gmail.com>
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16743
Cc: <stable@vger.kernel.org> # v6.18+
Tested-by: Annoy Cc <annoycc@gmail.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>
Link: https://patch.msgid.link/20260907034555.2753846-1-ankit.k.nautiyal@intel.com
(cherry picked from commit 550b703fdb)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Ankit Nautiyal 2026-09-07 09:15:55 +05:30 • committed by Jani Nikula
commit 5271d81f99