From eae66b50c760233fad526edf4a0d327be17a055d Mon Sep 17 00:00:00 2001 From: Eugeni Dodonov Date: Wed, 8 Feb 2012 12:53:49 -0800 Subject: [PATCH] drm/i915: gen7: implement rczunit workaround 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 Signed-off-by: Eugeni Dodonov Signed-off-by: Kenneth Graunke Signed-off-by: Jesse Barnes --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_display.c | 5 +++++ 2 files changed, 6 insertions(+) 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 b3b51c4..643c525 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, -- 2.7.4