thr3ads.net - Nouveau - [Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations [Jun 2021]

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Lyude Paul

2021-May-14 18:14 UTC

[Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations

Noticed this while moving all of the VESA backlight code in i915 over to
DRM helpers: it would appear that we calculate the frequency value we want
to write to DP_EDP_BACKLIGHT_FREQ_SET twice even though this value never
actually changes during runtime. So, let's simplify things by just caching
this value in intel_panel.backlight, and re-writing it as-needed.

Changes since v1:
* Wrap panel->backlight.edp.vesa.pwm_freq_pre_divider in
  DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP check - Jani

Signed-off-by: Lyude Paul <lyude at redhat.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Dave Airlie <airlied at gmail.com>
Cc: greg.depoire at gmail.com
---
 .../drm/i915/display/intel_display_types.h    |  1 +
 .../drm/i915/display/intel_dp_aux_backlight.c | 65 ++++++-------------
 2 files changed, 20 insertions(+), 46 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
b/drivers/gpu/drm/i915/display/intel_display_types.h
index 9c0adfc60c6f..7054a37363fb 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -311,6 +311,7 @@ struct intel_panel {
 		union {
 			struct {
 				u8 pwmgen_bit_count;
+				u8 pwm_freq_pre_divider;
 			} vesa;
 			struct {
 				bool sdr_uses_aux;
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 8e9ac9ba1d38..68bfe50ada59 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -373,50 +373,6 @@ intel_dp_aux_vesa_set_backlight(const struct
drm_connector_state *conn_state,
 	}
 }
 
-/*
- * Set PWM Frequency divider to match desired frequency in vbt.
- * The PWM Frequency is calculated as 27Mhz / (F x P).
- * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the
- *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
- * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the
- *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
- */
-static bool intel_dp_aux_vesa_set_pwm_freq(struct intel_connector *connector)
-{
-	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
-	struct intel_dp *intel_dp = intel_attached_dp(connector);
-	const u8 pn = connector->panel.backlight.edp.vesa.pwmgen_bit_count;
-	int freq, fxp, f, fxp_actual, fxp_min, fxp_max;
-
-	freq = dev_priv->vbt.backlight.pwm_freq_hz;
-	if (!freq) {
-		drm_dbg_kms(&dev_priv->drm,
-			    "Use panel default backlight frequency\n");
-		return false;
-	}
-
-	fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq);
-	f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
-	fxp_actual = f << pn;
-
-	/* Ensure frequency is within 25% of desired value */
-	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
-	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
-
-	if (fxp_min > fxp_actual || fxp_actual > fxp_max) {
-		drm_dbg_kms(&dev_priv->drm, "Actual frequency out of
range\n");
-		return false;
-	}
-
-	if (drm_dp_dpcd_writeb(&intel_dp->aux,
-			       DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) {
-		drm_dbg_kms(&dev_priv->drm,
-			    "Failed to write aux backlight freq\n");
-		return false;
-	}
-	return true;
-}
-
 static void
 intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state,
 				   const struct drm_connector_state *conn_state, u32 level)
@@ -459,9 +415,13 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
 		break;
 	}
 
-	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
-		if (intel_dp_aux_vesa_set_pwm_freq(connector))
+	if (panel->backlight.edp.vesa.pwm_freq_pre_divider) {
+		if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET,
+				       panel->backlight.edp.vesa.pwm_freq_pre_divider) == 1)
 			new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
+		else
+			drm_dbg_kms(&i915->drm, "Failed to write aux backlight
frequency\n");
+	}
 
 	if (new_dpcd_buf != dpcd_buf) {
 		if (drm_dp_dpcd_writeb(&intel_dp->aux,
@@ -482,6 +442,14 @@ static void intel_dp_aux_vesa_disable_backlight(const
struct drm_connector_state
 				  false);
 }
 
+/*
+ * Compute PWM frequency divider value based off the frequency provided to us
by the vbt.
+ * The PWM Frequency is calculated as 27Mhz / (F x P).
+ * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the
+ *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
+ * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the
+ *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
+ */
 static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector
*connector)
 {
 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
@@ -533,8 +501,10 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct
intel_connector *connecto
 	pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
 	pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
 
+	/* Ensure frequency is within 25% of desired value */
 	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
 	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
+
 	if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) {
 		drm_dbg_kms(&i915->drm,
 			    "VBT defined backlight frequency out of range\n");
@@ -555,7 +525,10 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct
intel_connector *connecto
 			    "Failed to write aux pwmgen bit count\n");
 		return max_backlight;
 	}
+
 	panel->backlight.edp.vesa.pwmgen_bit_count = pn;
+	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
+		panel->backlight.edp.vesa.pwm_freq_pre_divider = f;
 
 	max_backlight = (1 << pn) - 1;
 
-- 
2.31.1

Rodrigo Vivi

2021-May-21 20:03 UTC

head link

[Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations

On Fri, May 14, 2021 at 02:14:55PM -0400, Lyude Paul
wrote:> Noticed this while moving all of the VESA backlight code in i915 over to
> DRM helpers: it would appear that we calculate the frequency value we want
> to write to DP_EDP_BACKLIGHT_FREQ_SET twice even though this value never
> actually changes during runtime. So, let's simplify things by just
caching
> this value in intel_panel.backlight, and re-writing it as-needed.
> 
> Changes since v1:
> * Wrap panel->backlight.edp.vesa.pwm_freq_pre_divider in
>   DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP check - Jani
This looks okay to me now... Jani, agree?
> 
> Signed-off-by: Lyude Paul <lyude at redhat.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Dave Airlie <airlied at gmail.com>
> Cc: greg.depoire at gmail.com
> ---
>  .../drm/i915/display/intel_display_types.h    |  1 +
>  .../drm/i915/display/intel_dp_aux_backlight.c | 65 ++++++-------------
>  2 files changed, 20 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 9c0adfc60c6f..7054a37363fb 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -311,6 +311,7 @@ struct intel_panel {
>  		union {
>  			struct {
>  				u8 pwmgen_bit_count;
> +				u8 pwm_freq_pre_divider;
>  			} vesa;
>  			struct {
>  				bool sdr_uses_aux;
> 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 8e9ac9ba1d38..68bfe50ada59 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -373,50 +373,6 @@ intel_dp_aux_vesa_set_backlight(const struct
drm_connector_state *conn_state,
>  	}
>  }
>  
> -/*
> - * Set PWM Frequency divider to match desired frequency in vbt.
> - * The PWM Frequency is calculated as 27Mhz / (F x P).
> - * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of
the
> - *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
> - * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the
> - *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
> - */
> -static bool intel_dp_aux_vesa_set_pwm_freq(struct intel_connector
*connector)
> -{
> -	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> -	struct intel_dp *intel_dp = intel_attached_dp(connector);
> -	const u8 pn = connector->panel.backlight.edp.vesa.pwmgen_bit_count;
> -	int freq, fxp, f, fxp_actual, fxp_min, fxp_max;
> -
> -	freq = dev_priv->vbt.backlight.pwm_freq_hz;
> -	if (!freq) {
> -		drm_dbg_kms(&dev_priv->drm,
> -			    "Use panel default backlight frequency\n");
> -		return false;
> -	}
> -
> -	fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq);
> -	f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
> -	fxp_actual = f << pn;
> -
> -	/* Ensure frequency is within 25% of desired value */
> -	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
> -	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
> -
> -	if (fxp_min > fxp_actual || fxp_actual > fxp_max) {
> -		drm_dbg_kms(&dev_priv->drm, "Actual frequency out of
range\n");
> -		return false;
> -	}
> -
> -	if (drm_dp_dpcd_writeb(&intel_dp->aux,
> -			       DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) {
> -		drm_dbg_kms(&dev_priv->drm,
> -			    "Failed to write aux backlight freq\n");
> -		return false;
> -	}
> -	return true;
> -}
> -
>  static void
>  intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state
*crtc_state,
>  				   const struct drm_connector_state *conn_state, u32 level)
> @@ -459,9 +415,13 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
>  		break;
>  	}
>  
> -	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
> -		if (intel_dp_aux_vesa_set_pwm_freq(connector))
> +	if (panel->backlight.edp.vesa.pwm_freq_pre_divider) {
> +		if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET,
> +				       panel->backlight.edp.vesa.pwm_freq_pre_divider) == 1)
>  			new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
> +		else
> +			drm_dbg_kms(&i915->drm, "Failed to write aux backlight
frequency\n");
> +	}
>  
>  	if (new_dpcd_buf != dpcd_buf) {
>  		if (drm_dp_dpcd_writeb(&intel_dp->aux,
> @@ -482,6 +442,14 @@ static void intel_dp_aux_vesa_disable_backlight(const
struct drm_connector_state
>  				  false);
>  }
>  
> +/*
> + * Compute PWM frequency divider value based off the frequency provided to
us by the vbt.
> + * The PWM Frequency is calculated as 27Mhz / (F x P).
> + * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of
the
> + *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
> + * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the
> + *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
> + */
>  static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector
*connector)
>  {
>  	struct drm_i915_private *i915 = to_i915(connector->base.dev);
> @@ -533,8 +501,10 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct
intel_connector *connecto
>  	pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
>  	pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
>  
> +	/* Ensure frequency is within 25% of desired value */
>  	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
>  	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
> +
>  	if (fxp_min < (1 << pn_min) || (255 << pn_max) <
fxp_max) {
>  		drm_dbg_kms(&i915->drm,
>  			    "VBT defined backlight frequency out of range\n");
> @@ -555,7 +525,10 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct
intel_connector *connecto
>  			    "Failed to write aux pwmgen bit count\n");
>  		return max_backlight;
>  	}
> +
>  	panel->backlight.edp.vesa.pwmgen_bit_count = pn;
> +	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
> +		panel->backlight.edp.vesa.pwm_freq_pre_divider = f;
>  
>  	max_backlight = (1 << pn) - 1;
>  
> -- 
> 2.31.1
>

Jani Nikula

2021-Jun-01 19:13 UTC

head link

[Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations

On Fri, 21 May 2021, Rodrigo Vivi <rodrigo.vivi at intel.com>
wrote:> On Fri, May 14, 2021 at 02:14:55PM -0400, Lyude Paul wrote:
>> Noticed this while moving all of the VESA backlight code in i915 over
to
>> DRM helpers: it would appear that we calculate the frequency value we
want
>> to write to DP_EDP_BACKLIGHT_FREQ_SET twice even though this value
never
>> actually changes during runtime. So, let's simplify things by just
caching
>> this value in intel_panel.backlight, and re-writing it as-needed.
>> 
>> Changes since v1:
>> * Wrap panel->backlight.edp.vesa.pwm_freq_pre_divider in
>>   DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP check - Jani
>
> This looks okay to me now... Jani, agree?
Reviewed-by: Jani Nikula <jani.nikula at intel.com>

>
>> 
>> Signed-off-by: Lyude Paul <lyude at redhat.com>
>> Cc: Jani Nikula <jani.nikula at intel.com>
>> Cc: Dave Airlie <airlied at gmail.com>
>> Cc: greg.depoire at gmail.com
>> ---
>>  .../drm/i915/display/intel_display_types.h    |  1 +
>>  .../drm/i915/display/intel_dp_aux_backlight.c | 65 ++++++-------------
>>  2 files changed, 20 insertions(+), 46 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
b/drivers/gpu/drm/i915/display/intel_display_types.h
>> index 9c0adfc60c6f..7054a37363fb 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
>> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
>> @@ -311,6 +311,7 @@ struct intel_panel {
>>  		union {
>>  			struct {
>>  				u8 pwmgen_bit_count;
>> +				u8 pwm_freq_pre_divider;
>>  			} vesa;
>>  			struct {
>>  				bool sdr_uses_aux;
>> 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 8e9ac9ba1d38..68bfe50ada59 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
>> @@ -373,50 +373,6 @@ intel_dp_aux_vesa_set_backlight(const struct
drm_connector_state *conn_state,
>>  	}
>>  }
>>  
>> -/*
>> - * Set PWM Frequency divider to match desired frequency in vbt.
>> - * The PWM Frequency is calculated as 27Mhz / (F x P).
>> - * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0
of the
>> - *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
>> - * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of
the
>> - *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
>> - */
>> -static bool intel_dp_aux_vesa_set_pwm_freq(struct intel_connector
*connector)
>> -{
>> -	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> -	struct intel_dp *intel_dp = intel_attached_dp(connector);
>> -	const u8 pn =
connector->panel.backlight.edp.vesa.pwmgen_bit_count;
>> -	int freq, fxp, f, fxp_actual, fxp_min, fxp_max;
>> -
>> -	freq = dev_priv->vbt.backlight.pwm_freq_hz;
>> -	if (!freq) {
>> -		drm_dbg_kms(&dev_priv->drm,
>> -			    "Use panel default backlight frequency\n");
>> -		return false;
>> -	}
>> -
>> -	fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq);
>> -	f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
>> -	fxp_actual = f << pn;
>> -
>> -	/* Ensure frequency is within 25% of desired value */
>> -	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
>> -	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
>> -
>> -	if (fxp_min > fxp_actual || fxp_actual > fxp_max) {
>> -		drm_dbg_kms(&dev_priv->drm, "Actual frequency out of
range\n");
>> -		return false;
>> -	}
>> -
>> -	if (drm_dp_dpcd_writeb(&intel_dp->aux,
>> -			       DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) {
>> -		drm_dbg_kms(&dev_priv->drm,
>> -			    "Failed to write aux backlight freq\n");
>> -		return false;
>> -	}
>> -	return true;
>> -}
>> -
>>  static void
>>  intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state
*crtc_state,
>>  				   const struct drm_connector_state *conn_state, u32 level)
>> @@ -459,9 +415,13 @@ intel_dp_aux_vesa_enable_backlight(const struct
intel_crtc_state *crtc_state,
>>  		break;
>>  	}
>>  
>> -	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
>> -		if (intel_dp_aux_vesa_set_pwm_freq(connector))
>> +	if (panel->backlight.edp.vesa.pwm_freq_pre_divider) {
>> +		if (drm_dp_dpcd_writeb(&intel_dp->aux,
DP_EDP_BACKLIGHT_FREQ_SET,
>> +				       panel->backlight.edp.vesa.pwm_freq_pre_divider) == 1)
>>  			new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
>> +		else
>> +			drm_dbg_kms(&i915->drm, "Failed to write aux backlight
frequency\n");
>> +	}
>>  
>>  	if (new_dpcd_buf != dpcd_buf) {
>>  		if (drm_dp_dpcd_writeb(&intel_dp->aux,
>> @@ -482,6 +442,14 @@ static void
intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state
>>  				  false);
>>  }
>>  
>> +/*
>> + * Compute PWM frequency divider value based off the frequency
provided to us by the vbt.
>> + * The PWM Frequency is calculated as 27Mhz / (F x P).
>> + * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0
of the
>> + *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
>> + * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of
the
>> + *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
>> + */
>>  static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector
*connector)
>>  {
>>  	struct drm_i915_private *i915 = to_i915(connector->base.dev);
>> @@ -533,8 +501,10 @@ static u32
intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto
>>  	pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
>>  	pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
>>  
>> +	/* Ensure frequency is within 25% of desired value */
>>  	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
>>  	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
>> +
>>  	if (fxp_min < (1 << pn_min) || (255 << pn_max) <
fxp_max) {
>>  		drm_dbg_kms(&i915->drm,
>>  			    "VBT defined backlight frequency out of range\n");
>> @@ -555,7 +525,10 @@ static u32
intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto
>>  			    "Failed to write aux pwmgen bit count\n");
>>  		return max_backlight;
>>  	}
>> +
>>  	panel->backlight.edp.vesa.pwmgen_bit_count = pn;
>> +	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
>> +		panel->backlight.edp.vesa.pwm_freq_pre_divider = f;
>>  
>>  	max_backlight = (1 << pn) - 1;
>>  
>> -- 
>> 2.31.1
>> 
-- 
Jani Nikula, Intel Open Source Graphics Center

Nouveau - Jun 2021 - [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations

[Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations

[Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations

[Nouveau] [PATCH v6 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations