releases/2.6.32.9/drm-i915-disable-sr-when-more-than-one-pipe-is-enabled.patch

   1 From 33c5fd121eabbccc9103daf6cda36941eb3c349f Mon Sep 17 00:00:00 2001
   2 From: David John <davidjon@xenontk.org>
   3 Date: Wed, 27 Jan 2010 15:19:08 +0530
   4 Subject: drm/i915: Disable SR when more than one pipe is enabled
   5
   6 From: David John <davidjon@xenontk.org>
   7
   8 commit 33c5fd121eabbccc9103daf6cda36941eb3c349f upstream.
   9
  10 Self Refresh should be disabled on dual plane configs.  Otherwise, as
  11 the SR watermark is not calculated for such configs, switching to non
  12 VGA mode causes FIFO underrun and display flicker.
  13
  14 This fixes Korg Bug #14897.
  15
  16 Signed-off-by: David John <davidjon@xenontk.org>
  17 Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
  18 Signed-off-by: Eric Anholt <eric@anholt.net>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  20
  21 ---
  22  drivers/gpu/drm/i915/intel_display.c |   12 ++++++++++++
  23  1 file changed, 12 insertions(+)
  24
  25 --- a/drivers/gpu/drm/i915/intel_display.c
  26 +++ b/drivers/gpu/drm/i915/intel_display.c
  27 @@ -2538,6 +2538,10 @@ static void g4x_update_wm(struct drm_dev
  28                 sr_entries = roundup(sr_entries / cacheline_size, 1);
  29                 DRM_DEBUG("self-refresh entries: %d\n", sr_entries);
  30                 I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
  31 +       } else {
  32 +               /* Turn off self refresh if both pipes are enabled */
  33 +               I915_WRITE(FW_BLC_SELF, I915_READ(FW_BLC_SELF)
  34 +                                       & ~FW_BLC_SELF_EN);
  35         }
  36
  37         DRM_DEBUG("Setting FIFO watermarks - A: %d, B: %d, SR %d\n",
  38 @@ -2581,6 +2585,10 @@ static void i965_update_wm(struct drm_de
  39                         srwm = 1;
  40                 srwm &= 0x3f;
  41                 I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
  42 +       } else {
  43 +               /* Turn off self refresh if both pipes are enabled */
  44 +               I915_WRITE(FW_BLC_SELF, I915_READ(FW_BLC_SELF)
  45 +                                       & ~FW_BLC_SELF_EN);
  46         }
  47
  48         DRM_DEBUG_KMS("Setting FIFO watermarks - A: 8, B: 8, C: 8, SR %d\n",
  49 @@ -2649,6 +2657,10 @@ static void i9xx_update_wm(struct drm_de
  50                 if (srwm < 0)
  51                         srwm = 1;
  52                 I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN | (srwm & 0x3f));
  53 +       } else {
  54 +               /* Turn off self refresh if both pipes are enabled */
  55 +               I915_WRITE(FW_BLC_SELF, I915_READ(FW_BLC_SELF)
  56 +                                       & ~FW_BLC_SELF_EN);
  57         }
  58
  59         DRM_DEBUG("Setting FIFO watermarks - A: %d, B: %d, C: %d, SR %d\n",