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From:   Stephen Boyd <swboyd@chromium.org>
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Date:   Thu, 22 Jul 2021 19:23:29 +0000
Message-ID: <CAE-0n539r5zQx7zX9bECspKUAypQ8VucgeMNTmqAjHOCemVmOg@mail.gmail.com>
Subject: Re: [PATCH v2 5/7] drm/msm/dp: return correct edid checksum after
 corrupted edid checksum read
To:     Kuogee Hsieh <khsieh@codeaurora.org>,
        dri-devel@lists.freedesktop.org, robdclark@gmail.com,
        sean@poorly.run
Cc:     abhinavk@codeaurora.org, aravindh@codeaurora.org, airlied@linux.ie,
        daniel@ffwll.ch, bjorn.andersson@linaro.org,
        linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
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Quoting Kuogee Hsieh (2021-07-13 08:54:05)
> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
> index 88196f7..0fdb551 100644
> --- a/drivers/gpu/drm/msm/dp/dp_panel.c
> +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
> @@ -303,7 +303,12 @@ void dp_panel_handle_sink_request(struct dp_panel *dp_panel)
>         panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
>
>         if (panel->link->sink_request & DP_TEST_LINK_EDID_READ) {
> -               u8 checksum = dp_panel_get_edid_checksum(dp_panel->edid);
> +               u8 checksum;
> +
> +               if (dp_panel->edid)
> +                       checksum = dp_panel_get_edid_checksum(dp_panel->edid);
> +               else
> +                       checksum = dp_panel->connector->real_edid_checksum;

Is there any reason why we can't use connector->real_edid_checksum all
the time?

>
>                 dp_link_send_edid_checksum(panel->link, checksum);
>                 dp_link_send_test_response(panel->link);