drm/i915: Don't wait for PCH on reset

BIOS should be setting this, but in case it doesn't...

v2: Define the bits we actually want to clear (Jesse)
Make it an RMW op (Jesse)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem.c

@@ -3992,6 +3992,12 @@ i915_gem_init_hw(struct drm_device *dev)
 	if (IS_HASWELL(dev) && (I915_READ(0x120010) == 1))
 		I915_WRITE(0x9008, I915_READ(0x9008) | 0xf0000);
 
+	if (HAS_PCH_NOP(dev)) {
+		u32 temp = I915_READ(GEN7_MSG_CTL);
+		temp &= ~(WAIT_FOR_PCH_FLR_ACK | WAIT_FOR_PCH_RESET_ACK);
+		I915_WRITE(GEN7_MSG_CTL, temp);
+	}
+
 	i915_gem_l3_remap(dev);
 
 	i915_gem_init_swizzling(dev);

drivers/gpu/drm/i915/i915_reg.h

@@ -3568,6 +3568,9 @@
 #define DISP_ARB_CTL	0x45000
 #define  DISP_TILE_SURFACE_SWIZZLING	(1<<13)
 #define  DISP_FBC_WM_DIS		(1<<15)
+#define GEN7_MSG_CTL	0x45010
+#define  WAIT_FOR_PCH_RESET_ACK		(1<<1)
+#define  WAIT_FOR_PCH_FLR_ACK		(1<<0)
 
 /* GEN7 chicken */
 #define GEN7_COMMON_SLICE_CHICKEN1		0x7010