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

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 9/7/2026 10:46 AM, Garg, Nemesa wrote:
>
>> -----Original Message-----
>> From: Intel-gfx <intel-gfx-bounces@lists.freedesktop.org> On Behalf Of Ankit
>> Nautiyal
>> Sent: Monday, September 7, 2026 9:16 AM
>> To: intel-gfx@lists.freedesktop.org; intel-xe@lists.freedesktop.org
>> Cc: jani.nikula@linux.intel.com; ville.syrjala@linux.intel.com;
>> annoycc@gmail.com; Nautiyal, Ankit K <ankit.k.nautiyal@intel.com>;
>> stable@vger.kernel.org
>> Subject: [PATCH] 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 8c9006283e4b ("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: 8c9006283e4b ("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>
>> ---
>>   drivers/gpu/drm/i915/display/intel_quirks.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c
>> b/drivers/gpu/drm/i915/display/intel_quirks.c
>> index 33245f44c0d5..7d7db774d8c7 100644
>> --- a/drivers/gpu/drm/i915/display/intel_quirks.c
>> +++ b/drivers/gpu/drm/i915/display/intel_quirks.c
>> @@ -257,6 +257,9 @@ static struct intel_quirk intel_quirks[] = {
>>   	/* Dell XPS 13 7390 2-in-1 */
>>   	{ 0x8a52, 0x1028, 0x08b0, quirk_edp_limit_rate_hbr2 },
>>
>> +	/* HP Pavilion Plus Laptop 14-ew1xxx */
>> +	{ 0x7d55, 0x103c, 0x8c31, quirk_edp_limit_rate_hbr2 },
>> +
> LGTM,
> Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>


Thanks Nemesa for the review, pushed to drm-intel-next.


Regards,

Ankit

>
>>   	/* Xiaomi Book Pro 14 2026 */
>>   	{ 0xb081, 0x1d72, 0x2424, quirk_disable_psr2 },  };
>> --
>> 2.50.1