drm/i915: Set two chicken bits implicated in missed IRQs on Ivybridge.

They don't fix our problems alone, but we're told to set them.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index eb44432d79bf..edced95aa75f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3020,6 +3020,10 @@
 #define   ILK_DPFC_DIS1         (1<<8)
 #define   ILK_DPFC_DIS2         (1<<9)
 
+#define IVB_CHICKEN3    0x4200c
+# define CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE      (1 << 5)
+# define CHICKEN3_DGMG_DONE_FIX_DISABLE         (1 << 2)
+
 #define DISP_ARB_CTL    0x45000
 #define  DISP_TILE_SURFACE_SWIZZLING    (1<<13)
 #define  DISP_FBC_WM_DIS                (1<<15)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 30397b74a4a3..2e00c8ae361c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8450,6 +8450,10 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
 
         I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);
 
+        I915_WRITE(IVB_CHICKEN3,
+                   CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE |
+                   CHICKEN3_DGMG_DONE_FIX_DISABLE);
+
         for_each_pipe(pipe) {
                 I915_WRITE(DSPCNTR(pipe),
                            I915_READ(DSPCNTR(pipe)) |