Attachment 142465 Details for Bug 108225 – Switch backlight to PWM mode on init.

[patch] Switch backlight to PWM mode on init.

file_108225.txt (text/plain), 1.88 KB, created by Maarten Lankhorst on 2018-11-14 13:39:14 UTC

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Creator: Maarten Lankhorst

Created: 2018-11-14 13:39:14 UTC

Size: 1.88 KB

patch

obsolete

>diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
>index e6cd7b55c018..ad056e0ab772 100644
>--- a/drivers/gpu/drm/i915/intel_panel.c
>+++ b/drivers/gpu/drm/i915/intel_panel.c
>@@ -1485,7 +1485,7 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus
> 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> 	struct intel_panel *panel = &connector->panel;
> 	u32 pch_ctl1, pch_ctl2, val;
>-	bool alt;
>+	bool alt, cpu_mode = false;
> 
> 	if (HAS_PCH_LPT(dev_priv))
> 		alt = I915_READ(SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY;
>@@ -1507,12 +1507,36 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus
> 
> 	panel->backlight.min = get_backlight_min_vbt(connector);
> 
>-	val = lpt_get_backlight(connector);
>+	panel->backlight.enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE;
>+	if (panel->backlight.enabled && HAS_PCH_LPT(dev_priv) &&
>+	    (I915_READ(BLC_PWM_CPU_CTL2) & BLM_PWM_ENABLE) &&
>+	    !WARN_ON(pch_ctl1 & BLM_PCH_OVERRIDE_ENABLE)) {
>+		u32 freq;
>+
>+		cpu_mode = true;
>+		/*
>+		 * We're in cpu mode, convert to PCH units.
>+		 *
>+		 * Convert CPU pwm tick back to hz, back to new PCH units again.
>+		 * this is the same formula as pch_hz_to_pwm, but the other way
>+		 * around..
>+		 */
>+		freq = DIV_ROUND_CLOSEST(KHz(dev_priv->rawclk_freq),
>+					pch_get_backlight(connector) * 128);
>+
>+		val = lpt_hz_to_pwm(connector, freq);
>+	} else
>+		val = lpt_get_backlight(connector);
> 	val = intel_panel_compute_brightness(connector, val);
> 	panel->backlight.level = clamp(val, panel->backlight.min,
> 				       panel->backlight.max);
> 
>-	panel->backlight.enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE;
>+	if (cpu_mode) {
>+		u32 tmp = I915_READ(BLC_PWM_CPU_CTL2);
>+		I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
>+
>+		lpt_enable_backlight(NULL, connector->base.state);
>+	}
> 
> 	return 0;
> }

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Attachments on bug 108225: 141889 | 141890 | 141891 | 141892 | 141893 | 141936 | 141937 | 141938 | 142461 | 142465 | 142472 | 142522 | 142667 | 142668

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