[PATCH 3.13 030/151] drm/i915: Don't clobber CHICKEN_PIPESL_1 on BDW

Kamal Mostafa kamal at canonical.com
Fri May 2 15:36:58 UTC 2014


3.13.11.1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala at linux.intel.com>

commit c7c656226842679bcd9f39dc24441b4ff398a850 upstream.

Misplaced parens cause us to totally clobber the CHICKEN_PIPESL_1
registers with 0xffffffff. Move the parens to the correct place
to avoid this.

In particular this caused bit 30 of said registers to be set, which
caused the sprite CSC to produce incorrect results.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72220
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau at intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
[ kamal: backport to 3.13 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 26c29c1..e2d10ce 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5314,8 +5314,8 @@ static void gen8_init_clock_gating(struct drm_device *dev)
 	/* WaPsrDPRSUnmaskVBlankInSRD */
 	for_each_pipe(i) {
 		I915_WRITE(CHICKEN_PIPESL_1(i),
-			   I915_READ(CHICKEN_PIPESL_1(i) |
-				     DPRS_MASK_VBLANK_SRD));
+			   I915_READ(CHICKEN_PIPESL_1(i)) |
+			   DPRS_MASK_VBLANK_SRD);
 	}
 }
 
-- 
1.9.1





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