[PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

[Lyude Paul]

Seems reasonable to me:

Reviewed-by: Lyude Paul <lyude at redhat.com>

On Wed, 2021-05-19 at 17:53 +0800, Aaron Ma wrote:
> Another Samsung OLED panel needs DPCD to get control of backlight.
> Kernel 5.12+ support the backlight via:
> commit: <4a8d79901d5b> ("drm/i915/dp: Enable Intel's HDR backlight interface
> (only SDR for now)")
> Only make backlight work on lower versions of kernel.
> 
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3474
> Cc: stable at vger.kernel.org # 5.11-
> Signed-off-by: Aaron Ma <aaron.ma at canonical.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 5bd0934004e3..7b91d8a76cd6 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -1960,6 +1960,7 @@ static const struct edid_quirk edid_quirk_list[] = {
>         { MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>         { MFG(0x4c, 0x83), PROD_ID(0x47, 0x41),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>         { MFG(0x09, 0xe5), PROD_ID(0xde, 0x08),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
> +       { MFG(0x4c, 0x83), PROD_ID(0x57, 0x41),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>  };
>  
>  #undef MFG

-- 
Sincerely,
   Lyude Paul (she/her)
   Software Engineer at Red Hat
   
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