Re: [Freedreno] [PATCH] drm/msm/dp: skip validity check for DP CTS EDID checksum

[Jani Nikula <jani.nikula@intel.com>]

On Tue, 12 Sep 2023, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
> Hi Jani
>
> On 9/12/2023 5:16 AM, Jani Nikula wrote:
>> On Thu, 07 Sep 2023, Stephen Boyd <swboyd@chromium.org> wrote:
>>> Quoting Jani Nikula (2023-09-01 07:20:34)
>>>> The DP CTS test for EDID last block checksum expects the checksum for
>>>> the last block, invalid or not. Skip the validity check.
>>>>
>>>> For the most part (*), the EDIDs returned by drm_get_edid() will be
>>>> valid anyway, and there's the CTS workaround to get the checksum for
>>>> completely invalid EDIDs. See commit 7948fe12d47a ("drm/msm/dp: return
>>>> correct edid checksum after corrupted edid checksum read").
>>>>
>>>> This lets us remove one user of drm_edid_block_valid() with hopes the
>>>> function can be removed altogether in the future.
>>>>
>>>> (*) drm_get_edid() ignores checksum errors on CTA extensions.
>>>>
>>>> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>>> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>> Cc: Kuogee Hsieh <khsieh@codeaurora.org>
>>>> Cc: Marijn Suijten <marijn.suijten@somainline.org>
>>>> Cc: Rob Clark <robdclark@gmail.com>
>>>> Cc: Sean Paul <sean@poorly.run>
>>>> Cc: Stephen Boyd <swboyd@chromium.org>
>>>> Cc: linux-arm-msm@vger.kernel.org
>>>> Cc: freedreno@lists.freedesktop.org
>>>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>>>> ---
>>>
>>> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
>> 
>> Thanks; is that enough to merge? I can't claim I would have been able to
>> test this.
>> 
>
> Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>
> Change looks fine.
>
> We can pick this up in the MSM tree if you would like.

I'd appreciate that, thanks!

BR,
Jani.

>
> Dmitry, you can please pick this up along with my R-b and Kuogee's R-b 
> as well.
>
> I think his R-b got misformatted. I can ask him to add that again.
>
>>>
>>>>
>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
>>>> index 42d52510ffd4..86a8e06c7a60 100644
>>>> --- a/drivers/gpu/drm/msm/dp/dp_panel.c
>>>> +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
>>>> @@ -289,26 +289,9 @@ int dp_panel_get_modes(struct dp_panel *dp_panel,
>>>>
>>>>   static u8 dp_panel_get_edid_checksum(struct edid *edid)
>>>
>>> It would be nice to make 'edid' const here in another patch.
>> 
>> Sure.
>> 
>> BR,
>> Jani.
>> 
>> 

-- 
Jani Nikula, Intel