thr3ads.net - Nouveau - [Nouveau] [PATCH v3 1/5] drm/i915: Add support for panels with VESA backlights with PWM enable/disable [Oct 2021]

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Lyude Paul

2021-Oct-06 02:40 UTC

[Nouveau] [PATCH v3 1/5] drm/i915: Add support for panels with VESA backlights with PWM enable/disable

This simply adds proper support for panel backlights that can be controlled
via VESA's backlight control protocol, but which also require that we
enable and disable the backlight via PWM instead of via the DPCD interface.
We also enable this by default, in order to fix some people's backlights
that were broken by not having this enabled.

For reference, backlights that require this and use VESA's backlight
interface tend to be laptops with hybrid GPUs, but this very well may
change in the future.

Signed-off-by: Lyude Paul <lyude at redhat.com>
Link: https://gitlab.freedesktop.org/drm/intel/-/issues/3680
Fixes: fe7d52bccab6 ("drm/i915/dp: Don't use DPCD backlights that need
PWM enable/disable")
Cc: <stable at vger.kernel.org> # v5.12+
---
 .../drm/i915/display/intel_dp_aux_backlight.c | 24 ++++++++++++++-----
 1 file changed, 18 insertions(+), 6 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 569d17b4d00f..594fdc7453ca 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -293,6 +293,10 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
 	struct intel_panel *panel = &connector->panel;
 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
 
+	if (!panel->backlight.edp.vesa.info.aux_enable)
+		panel->backlight.pwm_funcs->enable(crtc_state, conn_state,
+						   panel->backlight.pwm_level_max);
+
 	drm_edp_backlight_enable(&intel_dp->aux,
&panel->backlight.edp.vesa.info, level);
 }
 
@@ -304,6 +308,10 @@ static void intel_dp_aux_vesa_disable_backlight(const
struct drm_connector_state
 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
 
 	drm_edp_backlight_disable(&intel_dp->aux,
&panel->backlight.edp.vesa.info);
+
+	if (!panel->backlight.edp.vesa.info.aux_enable)
+		panel->backlight.pwm_funcs->disable(old_conn_state,
+						    intel_backlight_invert_pwm_level(connector, 0));
 }
 
 static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
enum pipe pipe)
@@ -321,6 +329,15 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
 	if (ret < 0)
 		return ret;
 
+	if (!panel->backlight.edp.vesa.info.aux_enable) {
+		ret = panel->backlight.pwm_funcs->setup(connector, pipe);
+		if (ret < 0) {
+			drm_err(&i915->drm,
+				"Failed to setup PWM backlight controls for eDP backlight: %d\n",
+				ret);
+			return ret;
+		}
+	}
 	panel->backlight.max = panel->backlight.edp.vesa.info.max;
 	panel->backlight.min = 0;
 	if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
@@ -340,12 +357,7 @@ intel_dp_aux_supports_vesa_backlight(struct intel_connector
*connector)
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 
-	/* TODO: We currently only support AUX only backlight configurations, not
backlights which
-	 * require a mix of PWM and AUX controls to work. In the mean time, these
machines typically
-	 * work just fine using normal PWM controls anyway.
-	 */
-	if ((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)
&&
-	    drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
+	if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
 		drm_dbg_kms(&i915->drm, "AUX Backlight Control
Supported!\n");
 		return true;
 	}
-- 
2.31.1

Ville Syrjälä

2021-Oct-19 18:09 UTC

head link

[Nouveau] [PATCH v3 1/5] drm/i915: Add support for panels with VESA backlights with PWM enable/disable

On Tue, Oct 05, 2021 at 10:40:14PM -0400, Lyude Paul
wrote:> This simply adds proper support for panel backlights that can be controlled
> via VESA's backlight control protocol, but which also require that we
> enable and disable the backlight via PWM instead of via the DPCD interface.
> We also enable this by default, in order to fix some people's
backlights
> that were broken by not having this enabled.
> 
> For reference, backlights that require this and use VESA's backlight
> interface tend to be laptops with hybrid GPUs, but this very well may
> change in the future.
> 
> Signed-off-by: Lyude Paul <lyude at redhat.com>
> Link: https://gitlab.freedesktop.org/drm/intel/-/issues/3680
> Fixes: fe7d52bccab6 ("drm/i915/dp: Don't use DPCD backlights that
need PWM enable/disable")
> Cc: <stable at vger.kernel.org> # v5.12+
> ---
>  .../drm/i915/display/intel_dp_aux_backlight.c | 24 ++++++++++++++-----
>  1 file changed, 18 insertions(+), 6 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 569d17b4d00f..594fdc7453ca 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -293,6 +293,10 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
>  	struct intel_panel *panel = &connector->panel;
>  	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
>  
> +	if (!panel->backlight.edp.vesa.info.aux_enable)
> +		panel->backlight.pwm_funcs->enable(crtc_state, conn_state,
> +						   panel->backlight.pwm_level_max);
What't the story here with the non-inverted max vs. pontetially inverted
0 in the counterpart?
> +
>  	drm_edp_backlight_enable(&intel_dp->aux,
&panel->backlight.edp.vesa.info, level);
>  }
>  
> @@ -304,6 +308,10 @@ static void intel_dp_aux_vesa_disable_backlight(const
struct drm_connector_state
>  	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
>  
>  	drm_edp_backlight_disable(&intel_dp->aux,
&panel->backlight.edp.vesa.info);
> +
> +	if (!panel->backlight.edp.vesa.info.aux_enable)
> +		panel->backlight.pwm_funcs->disable(old_conn_state,
> +						    intel_backlight_invert_pwm_level(connector, 0));
>  }
>  
>  static int intel_dp_aux_vesa_setup_backlight(struct intel_connector
*connector, enum pipe pipe)
> @@ -321,6 +329,15 @@ static int intel_dp_aux_vesa_setup_backlight(struct
intel_connector *connector,
>  	if (ret < 0)
>  		return ret;
>  
> +	if (!panel->backlight.edp.vesa.info.aux_enable) {
> +		ret = panel->backlight.pwm_funcs->setup(connector, pipe);
> +		if (ret < 0) {
> +			drm_err(&i915->drm,
> +				"Failed to setup PWM backlight controls for eDP backlight:
%d\n",
> +				ret);
> +			return ret;
> +		}
> +	}
>  	panel->backlight.max = panel->backlight.edp.vesa.info.max;
>  	panel->backlight.min = 0;
>  	if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
> @@ -340,12 +357,7 @@ intel_dp_aux_supports_vesa_backlight(struct
intel_connector *connector)
>  	struct intel_dp *intel_dp = intel_attached_dp(connector);
>  	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
>  
> -	/* TODO: We currently only support AUX only backlight configurations, not
backlights which
> -	 * require a mix of PWM and AUX controls to work. In the mean time, these
machines typically
> -	 * work just fine using normal PWM controls anyway.
> -	 */
> -	if ((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)
&&
> -	    drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
> +	if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
>  		drm_dbg_kms(&i915->drm, "AUX Backlight Control
Supported!\n");
>  		return true;
>  	}
> -- 
> 2.31.1
-- 
Ville Syrj?l?
Intel

Nouveau - Oct 2021 - [PATCH v3 1/5] drm/i915: Add support for panels with VESA backlights with PWM enable/disable

[Nouveau] [PATCH v3 1/5] drm/i915: Add support for panels with VESA backlights with PWM enable/disable

[Nouveau] [PATCH v3 1/5] drm/i915: Add support for panels with VESA backlights with PWM enable/disable