drm/i915: set GFX_MODE to pre-Ivybridge default value even on Ivybridge

Prior to Ivybridge, the GFX_MODE would default to 0x800, meaning that
MI_FLUSH would flush the TLBs in addition to the rest of the caches
indicated in the MI_FLUSH command.  However starting with Ivybridge, the
register defaults to 0x2800 out of reset, meaning that to invalidate the
TLB we need to use PIPE_CONTROL.  Since we're not doing that yet, go
back to the old default so things work.

v2: don't forget to actually *clear* the new bit

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

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 5baaef4a0c5d..542453f7498c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -375,6 +375,7 @@
 # define MI_FLUSH_ENABLE                                (1 << 11)
 
 #define GFX_MODE        0x02520
+#define GFX_MODE_GEN7   0x0229c
 #define   GFX_RUN_LIST_ENABLE           (1<<15)
 #define   GFX_TLB_INVALIDATE_ALWAYS     (1<<13)
 #define   GFX_SURFACE_FAULT_ENABLE      (1<<12)
@@ -382,6 +383,9 @@
 #define   GFX_PSMI_GRANULARITY          (1<<10)
 #define   GFX_PPGTT_ENABLE              (1<<9)
 
+#define GFX_MODE_ENABLE(bit) (((bit) << 16) | (bit))
+#define GFX_MODE_DISABLE(bit) (((bit) << 16) | (0))
+
 #define SCPD0           0x0209c /* 915+ only */
 #define IER             0x020a0
 #define IIR             0x020a4
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 47b9b2777038..c30626ea9f93 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -290,6 +290,10 @@ static int init_render_ring(struct intel_ring_buffer *ring)
                 if (IS_GEN6(dev) || IS_GEN7(dev))
                         mode |= MI_FLUSH_ENABLE << 16 | MI_FLUSH_ENABLE;
                 I915_WRITE(MI_MODE, mode);
+                if (IS_GEN7(dev))
+                        I915_WRITE(GFX_MODE_GEN7,
+                                   GFX_MODE_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
+                                   GFX_MODE_ENABLE(GFX_REPLAY_MODE));
         }
 
         if (INTEL_INFO(dev)->gen >= 6) {