From: Eugeni Dodonov <[email protected]>

This is yet another workaround related to clock gating which we need on
Ivy Bridge.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41353
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44610
Tested-by: Eugeni Dodonov <[email protected]>
Signed-off-by: Eugeni Dodonov <[email protected]>
Signed-off-by: Kenneth Graunke <[email protected]>
---
 drivers/gpu/drm/i915/i915_reg.h      |    1 +
 drivers/gpu/drm/i915/intel_display.c |    5 +++++
 2 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c3afb78..80fd6b5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3618,6 +3618,7 @@
 #define    GT_FIFO_NUM_RESERVED_ENTRIES                20
 
 #define GEN6_UCGCTL2                           0x9404
+# define GEN6_RCZUNIT_CLOCK_GATE_DISABLE               (1 << 13)
 # define GEN6_RCPBUNIT_CLOCK_GATE_DISABLE              (1 << 12)
 # define GEN6_RCCUNIT_CLOCK_GATE_DISABLE               (1 << 11)
 
diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index f1744aa..070c946 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8461,6 +8461,11 @@ static void ivybridge_init_clock_gating(struct 
drm_device *dev)
        I915_WRITE(WM2_LP_ILK, 0);
        I915_WRITE(WM1_LP_ILK, 0);
 
+       /* According to the spec, bit 13 (RCZUNIT) must be set on IVB.
+        * This implements the WaDisableRCZUnitClockGating workaround.
+        */
+       I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE);
+
        I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);
 
        I915_WRITE(IVB_CHICKEN3,
-- 
1.7.7.1

_______________________________________________
Intel-gfx mailing list
[email protected]
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to