Re: [PATCH v3 4/5] drm/dp, drm/i915: Add support for VESA backlights using PWM for brightness control

[Doug Anderson]

Hi,

On Tue, Oct 5, 2021 at 7:41 PM Lyude Paul <lyude@xxxxxxxxxx> wrote:
>
> @@ -1859,8 +1859,7 @@ drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>  static inline bool
>  drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
>  {
> -       return (edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
> -               (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP);
> +       return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
>  }

nit: I don't believe that the "!!" is needed in the above. C should
automatically handle this since the return type of the function is
"bool".

I've reviewed the generic (non-intel) code and it looks like a
reasonable approach to me.

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>