From 37c6c9b0e941fbb7f37a93d36abaf5fcafea87a8 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Wed, 11 Aug 2010 10:04:43 -0700 Subject: [PATCH] drm/i915: add panel reset workaround Ironlake requires that we clear the reset panel bit during power sequences and restore it afterwards. Uncondtionally add code to do that since it should be harmless on SNB+. Signed-off-by: Jesse Barnes --- drivers/gpu/drm/i915/intel_dp.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c6629bd9430f..d1b4ece4df00 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -765,6 +765,12 @@ static void ironlake_edp_panel_on (struct drm_device *dev) return; pp = I915_READ(PCH_PP_CONTROL); + + /* ILK workaround: disable reset around power sequence */ + pp &= ~PANEL_POWER_RESET; + I915_WRITE(PCH_PP_CONTROL, pp); + POSTING_READ(PCH_PP_CONTROL); + pp |= PANEL_UNLOCK_REGS | POWER_TARGET_ON; I915_WRITE(PCH_PP_CONTROL, pp); @@ -773,7 +779,9 @@ static void ironlake_edp_panel_on (struct drm_device *dev) I915_READ(PCH_PP_STATUS)); pp &= ~(PANEL_UNLOCK_REGS | EDP_FORCE_VDD); + pp |= PANEL_POWER_RESET; /* restore panel reset bit */ I915_WRITE(PCH_PP_CONTROL, pp); + POSTING_READ(PCH_PP_CONTROL); } static void ironlake_edp_panel_off (struct drm_device *dev) @@ -782,6 +790,12 @@ static void ironlake_edp_panel_off (struct drm_device *dev) u32 pp; pp = I915_READ(PCH_PP_CONTROL); + + /* ILK workaround: disable reset around power sequence */ + pp &= ~PANEL_POWER_RESET; + I915_WRITE(PCH_PP_CONTROL, pp); + POSTING_READ(PCH_PP_CONTROL); + pp &= ~POWER_TARGET_ON; I915_WRITE(PCH_PP_CONTROL, pp); @@ -790,8 +804,9 @@ static void ironlake_edp_panel_off (struct drm_device *dev) I915_READ(PCH_PP_STATUS)); /* Make sure VDD is enabled so DP AUX will work */ - pp |= EDP_FORCE_VDD; + pp |= EDP_FORCE_VDD | PANEL_POWER_RESET; /* restore panel reset bit */ I915_WRITE(PCH_PP_CONTROL, pp); + POSTING_READ(PCH_PP_CONTROL); } static void ironlake_edp_backlight_on (struct drm_device *dev) -- 2.20.1