From 27d64339a8d8465484286a2da93f5f6c36be5c3d Mon Sep 17 00:00:00 2001 From: Hette Visser Date: Fri, 24 Sep 2010 10:51:30 +0100 Subject: [PATCH] drm/i915/dp: Wait for PP_CONTROL to take effect. This patch fixes the black screen bug on Dell e6510, by adding two delays to give the eDP panel time to turn on before we continue with the next write. 300ms is rather arbitray and a rather long sleep, we need to find a way of refining this value. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29278 Signed-off-by: Chris Wilson Acked-by: Jesse Barnes --- drivers/gpu/drm/i915/intel_dp.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 117eb998825..d19334aa66a 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -784,6 +784,11 @@ static bool ironlake_edp_panel_on (struct drm_device *dev) pp |= POWER_TARGET_ON; I915_WRITE(PCH_PP_CONTROL, pp); + /* Ouch. We need to wait here for some panels, like Dell e6510 + * https://bugs.freedesktop.org/show_bug.cgi?id=29278i + */ + msleep(300); + if (wait_for(I915_READ(PCH_PP_STATUS) & PP_ON, 5000)) DRM_ERROR("panel on wait timed out: 0x%08x\n", I915_READ(PCH_PP_STATUS)); @@ -819,6 +824,11 @@ static void ironlake_edp_panel_off (struct drm_device *dev) pp |= PANEL_POWER_RESET; /* restore panel reset bit */ I915_WRITE(PCH_PP_CONTROL, pp); POSTING_READ(PCH_PP_CONTROL); + + /* Ouch. We need to wait here for some panels, like Dell e6510 + * https://bugs.freedesktop.org/show_bug.cgi?id=29278i + */ + msleep(300); } static void ironlake_edp_panel_vdd_on(struct drm_device *dev) -- 2.46.0