[Intel-gfx] [PATCH] drm/i915: Fix black screen bug on Dell e6510

[Hette Visser]

This patch fixes the black screen bug on Dell e6510:
https://bugs.freedesktop.org/show_bug.cgi?id=29278

It adds two delays to give the eDP panel time to turn on before we
continue with the next write.


--- drivers/gpu/drm/i915/intel_dp.c.orig	2010-09-23 20:13:36.046856913 +0200
+++ drivers/gpu/drm/i915/intel_dp.c	2010-09-23 19:27:00.682282002 +0200
@@ -27,6 +27,7 @@

 #include <linux/i2c.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #include "drmP.h"
 #include "drm.h"
 #include "drm_crtc.h"
@@ -772,6 +773,7 @@ static void ironlake_edp_panel_on (struc
 	pp |= PANEL_UNLOCK_REGS | POWER_TARGET_ON;
 	I915_WRITE(PCH_PP_CONTROL, pp);

+	msleep(300);
 	if (wait_for(I915_READ(PCH_PP_STATUS) & PP_ON, 5000, 10))
 		DRM_ERROR("panel on wait timed out: 0x%08x\n",
 			  I915_READ(PCH_PP_STATUS));
@@ -805,6 +807,7 @@ static void ironlake_edp_panel_off (stru
 	pp |= EDP_FORCE_VDD | PANEL_POWER_RESET; /* restore panel reset bit */
 	I915_WRITE(PCH_PP_CONTROL, pp);
 	POSTING_READ(PCH_PP_CONTROL);
+	msleep(300);
 }