Attachment 66927 Details for Bug 44156 – always use LBPC 0xff in combination mode

[patch] always use LBPC 0xff in combination mode

0001-drm-i915-always-use-LBPC-0xff-in-combination-legacy-.patch (text/plain), 1.86 KB, created by Jani Nikula on 2012-09-10 12:46:37 UTC

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Creator: Jani Nikula

Created: 2012-09-10 12:46:37 UTC

Size: 1.86 KB

patch

obsolete

>From cb978754b052f209cd8e80e09ed1e7fd5b878e3c Mon Sep 17 00:00:00 2001
>From: Jani Nikula <jani.nikula@intel.com>
>Date: Mon, 10 Sep 2012 15:17:33 +0300
>Subject: [PATCH] drm/i915: always use LBPC 0xff in combination/legacy mode
>
>LBPC value 0xff means it's not used for duty cycle multiplication per gen2
>and gen4 display register specs. Keep LBPC at 0xff at all times and drop
>the brightness range multiplication in combination/legacy mode to hopefully
>avoid backlight issues and simplify code.
>
>Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>---
> drivers/gpu/drm/i915/intel_panel.c |   16 ++++------------
> 1 file changed, 4 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
>index 3df4f5f..8704947 100644
>--- a/drivers/gpu/drm/i915/intel_panel.c
>+++ b/drivers/gpu/drm/i915/intel_panel.c
>@@ -183,9 +183,6 @@ u32 intel_panel_get_max_backlight(struct drm_device *dev)
> 			max >>= 17;
> 		else
> 			max >>= 16;
>-
>-		if (is_backlight_combination_mode(dev))
>-			max *= 0xff;
> 	}
> 
> 	DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
>@@ -229,7 +226,8 @@ static u32 intel_panel_get_backlight(struct drm_device *dev)
> 			u8 lbpc;
> 
> 			pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
>-			val *= lbpc;
>+			if (lbpc != 0xff)
>+				val = val * lbpc / 0xfe;
> 		}
> 	}
> 
>@@ -256,14 +254,8 @@ static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level
> 	if (HAS_PCH_SPLIT(dev))
> 		return intel_pch_panel_set_backlight(dev, level);
> 
>-	if (is_backlight_combination_mode(dev)) {
>-		u32 max = intel_panel_get_max_backlight(dev);
>-		u8 lbpc;
>-
>-		lbpc = level * 0xfe / max + 1;
>-		level /= lbpc;
>-		pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
>-	}
>+	if (is_backlight_combination_mode(dev))
>+		pci_write_config_byte(dev->pdev, PCI_LBPC, 0xff);
> 
> 	tmp = I915_READ(BLC_PWM_CTL);
> 	if (INTEL_INFO(dev)->gen < 4) 
>-- 
>1.7.9.5
>

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Attachments on bug 44156: 54829 | 54830 | 54831 | 55022 | 55023 | 55024 | 60759 | 62695 | 62696 | 62699 | 62700 | 62761 | 62762 | 66927 | 71761 | 73445

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