linux-kernel - Re: [Freedreno] [PATCH v4 1/5] msm/drm/dsi: Round up DSC hdisplay calculation

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

Message-ID: <3935b919-58ee-e8c6-826f-7ebdff980524@quicinc.com>
Date:   Mon, 22 May 2023 15:08:36 -0700
From:   Jessica Zhang <quic_jesszhan@...cinc.com>
To:     Marijn Suijten <marijn.suijten@...ainline.org>
CC:     <freedreno@...ts.freedesktop.org>, Sean Paul <sean@...rly.run>,
        "Abhinav Kumar" <quic_abhinavk@...cinc.com>,
        <dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        "Rob Clark" <robdclark@...il.com>, Daniel Vetter <daniel@...ll.ch>,
        <linux-arm-msm@...r.kernel.org>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        David Airlie <airlied@...il.com>
Subject: Re: [Freedreno] [PATCH v4 1/5] msm/drm/dsi: Round up DSC hdisplay
 calculation



On 5/22/2023 2:45 PM, Jessica Zhang wrote:
> 
> 
> On 5/22/2023 1:44 PM, Marijn Suijten wrote:
>> On 2023-05-22 13:30:20, Jessica Zhang wrote:
>>> Currently, when compression is enabled, hdisplay is reduced via integer
>>> division. This causes issues for modes where the original hdisplay is
>>> not a multiple of 3.
>>>
>>> To fix this, use DIV_ROUND_UP to divide hdisplay.
>>>
>>> Reviewed-by: Marijn Suijten <marijn.suijten@...ainline.org>
>>> Suggested-by: Marijn Suijten <marijn.suijten@...ainline.org>
>>
>> Nit: probably these should go in the opposite order.  And if they're
>> all supposed to be chronological, I think it is:
>>
>>      Suggested-by:
>>      Fixes:
>>      Signed-off-by:
>>      Reviewed-by:
>>
>> But unsure if that's a hard requirement, or even correct at all.
> 
> Hi Marijn,
> 
> I don't see any explicit documentation on the order of R-b tags. FWIW, I 
> see in the git log that S-o-b always goes at the bottom of the commit 
> message.
> 
> I would prefer the S-o-b to always be at the bottom (as it helps me 
> avoid duplicate S-o-b's when doing `git commit -s`), though I can flip 
> the order of the R-b and suggested-by tags.

Correction -- I can reorder the tags so that it's:

Suggested-by:
Fixes:
Reviewed-by:
Signed-off-by:

Thanks,

Jessica Zhang

> 
> Thanks,
> 
> Jessica Zhang
> 
>>
>> - Marijn
>>
>>> Fixes: 08802f515c3cf ("drm/msm/dsi: Add support for DSC configuration")
>>> Signed-off-by: Jessica Zhang <quic_jesszhan@...cinc.com>
>>> ---
>>>   drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c 
>>> b/drivers/gpu/drm/msm/dsi/dsi_host.c
>>> index 9223d7ec5a73..18d38b90eb28 100644
>>> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
>>> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
>>> @@ -952,7 +952,7 @@ static void dsi_timing_setup(struct msm_dsi_host 
>>> *msm_host, bool is_bonded_dsi)
>>>            * pulse width same
>>>            */
>>>           h_total -= hdisplay;
>>> -        hdisplay = msm_dsc_get_bytes_per_line(msm_host->dsc) / 3;
>>> +        hdisplay = 
>>> DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc), 3);
>>>           h_total += hdisplay;
>>>           ha_end = ha_start + hdisplay;
>>>       }
>>>
>>> -- 
>>> 2.40.1
>>>