Message-ID: <52f48cb2-ce54-854f-3bec-44c40c6ad07f@tuxedocomputers.com>
Date:   Thu, 23 Feb 2023 19:56:12 +0100
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Subject: Re: [PATCH 0/2] Add quirk to disable PSR 2 on Tongfang PHxTxX1 and
 PHxTQx1
To:     "Hogander, Jouni" <jouni.hogander@intel.com>,
        "Souza, Jose" <jose.souza@intel.com>,
        "Santa Cruz, Diego" <Diego.SantaCruz@spinetix.com>,
        "Vivi, Rodrigo" <rodrigo.vivi@intel.com>,
        "ville.syrjala@linux.intel.com" <ville.syrjala@linux.intel.com>,
        "joonas.lahtinen@linux.intel.com" <joonas.lahtinen@linux.intel.com>,
        "Kahola, Mika" <mika.kahola@intel.com>,
        "airlied@gmail.com" <airlied@gmail.com>,
        "tvrtko.ursulin@linux.intel.com" <tvrtko.ursulin@linux.intel.com>,
        "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "daniel@ffwll.ch" <daniel@ffwll.ch>,
        "jani.nikula@linux.intel.com" <jani.nikula@linux.intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "De Marchi, Lucas" <lucas.demarchi@intel.com>
References: <20230222141755.1060162-1-wse@tuxedocomputers.com>
 <9b0e29f15f3e8799256c425f06b36a70ec04522f.camel@intel.com>
Content-Language: en-US
From:   Werner Sembach <wse@tuxedocomputers.com>
In-Reply-To: <9b0e29f15f3e8799256c425f06b36a70ec04522f.camel@intel.com>
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Am 23.02.23 um 19:26 schrieb Hogander, Jouni:
> On Wed, 2023-02-22 at 15:17 +0100, Werner Sembach wrote:
>> On these Barebones PSR 2 is recognized as supported but is very
>> buggy:
>> - Upper third of screen does sometimes not updated, resulting in
>> disappearing cursors or ghosts of already closed Windows saying
>> behind.
>> - Approximately 40 px from the bottom edge a 3 pixel wide strip of
>> randomly
>> colored pixels is flickering.
>>
>> PSR 1 is working fine however.
>>
>> This patchset introduces a new quirk to disable PSR 2 specifically on
>> known
>> buggy devices and applies it to the Tongfang PHxTxX1 and PHxTQx1
>> barebones.
> I've been thinking something similar as there is still at least one
> issue which seems to be like panel side issue:
>
> https://gitlab.freedesktop.org/drm/intel/-/issues/7836
>
> Did you considered dpcd_quirk_list in drivers/gpu/drm/drm_dp_helper.c?
>
> I'm not sure which one is more correct though...
Imho, since the proper fix lies within the Intel driver the quirk should also 
lie within the Intel driver, because even if the panel has the same problem 
combined with an AMD or NVIDIA card the proper fix for them will most likely be 
land in the same kernel version. So there could be a period where you no longer 
want the quirk for devices combining the panel with an Intel gpu but still with 
an AMD GPU or vice versa.
>
>> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
>> Cc: <stable@vger.kernel.org>
>>
>>