From 729e612335ca72f8ce4a1bb19b893d44f738daf6 Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Fri, 13 Jul 2012 18:49:16 -0300 Subject: [PATCH] drm/i915: don't forget the PCH backlight registers When we enable/disable the CPU backlight registers we can't forget to enable/disable the PCH backlight registers. Since we're using the CPU registers we should also unset the override bit. Fixes a regression on the following commit: drm/i915: properly enable the blc controller on the right pipe The commit just deleted the code that sets the PCH registers, so it was relying on the values set by the BIOS. I told my BIOS to boot on the DVI monitor instead of the LVDS panel, so I noticed the bug. Signed-off-by: Paulo Zanoni --- drivers/gpu/drm/i915/intel_panel.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 58c7ee7..10c7d39 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -289,11 +289,17 @@ void intel_panel_disable_backlight(struct drm_device *dev) intel_panel_actually_set_backlight(dev, 0); if (INTEL_INFO(dev)->gen >= 4) { - uint32_t reg; + uint32_t reg, tmp; reg = HAS_PCH_SPLIT(dev) ? BLC_PWM_CPU_CTL2 : BLC_PWM_CTL2; I915_WRITE(reg, I915_READ(reg) & ~BLM_PWM_ENABLE); + + if (HAS_PCH_SPLIT(dev)) { + tmp = I915_READ(BLC_PWM_PCH_CTL1); + tmp &= ~BLM_PCH_PWM_ENABLE; + I915_WRITE(BLC_PWM_PCH_CTL1, tmp); + } } } @@ -333,6 +339,13 @@ void intel_panel_enable_backlight(struct drm_device *dev, I915_WRITE(reg, tmp); POSTING_READ(reg); I915_WRITE(reg, tmp | BLM_PWM_ENABLE); + + if (HAS_PCH_SPLIT(dev)) { + tmp = I915_READ(BLC_PWM_PCH_CTL1); + tmp |= BLM_PCH_PWM_ENABLE; + tmp &= ~BLM_PCH_OVERRIDE_ENABLE; + I915_WRITE(BLC_PWM_PCH_CTL1, tmp); + } } } -- 1.7.10.4