[PATCH 30/40] drm/i915: Add the WaCsStallBeforeStateCacheInvalidate:bdw workaround.

ville.syrjala
2014-06-27T23:08:37Z

From: Kenneth Graunke <kenneth@whitecape.org>

On Broadwell, any PIPE_CONTROL with the "State Cache Invalidate" bit set
must be preceded by a PIPE_CONTROL with the "CS Stall" bit set.

Documented on the BSpec 3D workarounds page.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
[vsyrjala: add chv w/a note too]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 97796b1..ceb1295 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -424,6 +424,14 @@ gen8_render_ring_flush(struct intel_engine_cs *ring,
flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_QW_WRITE;
flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
+
+ /* WaCsStallBeforeStateCacheInvalidate:bdw,chv */
+ ret = gen8_emit_pipe_control(ring,
+ PIPE_CONTROL_CS_STALL |
+ PIPE_CONTROL_STALL_AT_SCOREBOARD,
+ 0);
+ if (ret)
+ return ret;
}

return gen8_emit_pipe_control(ring, flags, scratch_addr);
--
1.8.5.5