linux-kernel - Re: [PATCH] drm/msm/dpu: Disable dither in phys encoder cleanup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <82da87d8-70d1-4013-ace7-ec90331d18e5@quicinc.com>
Date: Wed, 12 Feb 2025 17:20:35 -0800
From: Abhinav Kumar <quic_abhinavk@...cinc.com>
To: Jessica Zhang <quic_jesszhan@...cinc.com>,
        Rob Clark
	<robdclark@...il.com>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        "Sean
 Paul" <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        "David Airlie" <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
CC: <linux-arm-msm@...r.kernel.org>, <dri-devel@...ts.freedesktop.org>,
        <freedreno@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/msm/dpu: Disable dither in phys encoder cleanup



On 2/12/2025 12:23 PM, Abhinav Kumar wrote:
> 
> 
> On 2/11/2025 7:59 PM, Jessica Zhang wrote:
>> Disable pingpong dither in dpu_encoder_helper_phys_cleanup().
>>
>> This avoids the issue where an encoder unknowingly uses dither after
>> reserving a pingpong block that was previously bound to an encoder that
>> had enabled dither.
>>
>> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
>> Closes: https://lore.kernel.org/all/ 
>> jr7zbj5w7iq4apg3gofuvcwf4r2swzqjk7sshwcdjll4mn6ctt@...3qfpujg3q/
>> Signed-off-by: Jessica Zhang <quic_jesszhan@...cinc.com>
>> ---
>> This was tested on SC7180 Trogdor by pulling in the concurrent writeback
>> series [1] and running the IGT kms_writeback@...teback_check_output
>> subtest.
>>
>> [1] https://patchwork.freedesktop.org/series/144083/
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
> 
> Was an extremely tricky issue to debug.
> 
> Glad this one is resolved,
> 
> Reviewed-by: Abhinav Kumar <quic_abhinavk@...cinc.com>

Also going to add,

Fixes: 3c128638a07d ("drm/msm/dpu: add support for dither block in display")