blob: c6238bcdd36b5f536ea88a15a0b7a108e3ee764e [file] [log] [blame]
From fb88fbe4eac9862e5e257d6a4c32d6c44af2f3e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <>
Date: Fri, 4 Oct 2013 20:32:25 +0300
Subject: drm/i915: Fix VGA_DISP_DISABLE check
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The VGACNTRL register contains a bunch of other stuff besides
the VGA_DISP_DISABLE bit. When we write the register we always set those
other bits to zero, so normally the current check would work.
However on HSW disabling and re-enabling the power well will reset the
VGACNTRL register to its default value, which has several of the other
bits set as well.
So only look at the VGA_DISP_DISABLE bit when checking whether the VGA
plane needs re-disabling.
Signed-off-by: Ville Syrjälä <>
Reviewed-by: Jesse Barnes <>
Signed-off-by: Daniel Vetter <>
(cherry picked from commit e1553faa904f3f8bdd734ee1404ce39c652bc9c6)
Signed-off-by: Darren Hart <>
drivers/gpu/drm/i915/intel_display.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10665,7 +10665,7 @@ void i915_redisable_vga(struct drm_devic
- if (I915_READ(vga_reg) != VGA_DISP_DISABLE) {
+ if (!(I915_READ(vga_reg) & VGA_DISP_DISABLE)) {
DRM_DEBUG_KMS("Something enabled VGA plane, disabling it\n");