linux-kernel - (Cc: drm-misc/intel maintainers) Re: [PATCH 1/2] drm/i915/dpcd_bl: uncheck PWM_PIN_CAP when detect eDP backlight capabilities

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Date:   Fri, 09 Oct 2020 13:26:31 -0400
From:   Lyude Paul <lyude@...hat.com>
To:     Aaron Ma <aaron.ma@...onical.com>, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, intel-gfx@...ts.freedesktop.org,
        mapengyu@...il.com, daniel@...ll.ch, airlied@...ux.ie,
        tzimmermann@...e.de, mripard@...nel.org,
        maarten.lankhorst@...ux.intel.com, rodrigo.vivi@...el.com,
        joonas.lahtinen@...ux.intel.com, jani.nikula@...ux.intel.com,
        ville.syrjala@...ux.intel.com
Cc:     Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Maxime Ripard <maxime.ripard@...tlin.com>
Subject: (Cc: drm-misc/intel maintainers) Re: [PATCH 1/2] drm/i915/dpcd_bl:
 uncheck PWM_PIN_CAP when detect eDP backlight capabilities

For the whole series:

For the whole series:

Reviewed-by: Lyude Paul <lyude@...hat.com>

I'm going to add a Cc for stable so that it can be backported, and I'll push it
to drm-intel-next-queued once I get the OK from drm-misc/i915 folks

On Fri, 2020-10-09 at 16:57 +0800, Aaron Ma wrote:
> BOE panel with ID 2270 claims both PWM_PIN_CAP and AUX_SET_CAP backlight
> control bits, but default chip backlight failed to control brightness.
> 
> Check AUX_SET_CAP and proceed to check quirks or VBT backlight type.
> DPCD can control the brightness of this pannel.
> 
> Signed-off-by: Aaron Ma <aaron.ma@...onical.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> index acbd7eb66cbe..308b14159b7c 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -334,8 +334,7 @@ intel_dp_aux_display_control_capable(struct
> intel_connector *connector)
>  	 * the panel can support backlight control over the aux channel
>  	 */
>  	if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
> -	    (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) &&
> -	    !(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))
> {
> +	    (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
>  		drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n");
>  		return true;
>  	}
-- 
Sincerely,
      Lyude Paul (she/her)
      Software Engineer at Red Hat