[Intel-gfx] [PATCH 02/11] drm/i915: Add WaCsStallBeforeStateCacheInvalidate:bdw, chv to logical ring

[Rodrigo Vivi]

Similar to:

commit 02c9f7e3cfe76a7f54ef03438c36aade86cc1c8b
Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Mon Jan 27 14:20:16 2014 -0800

    drm/i915: Add the WaCsStallBeforeStateCacheInvalidate:bdw workaround.

    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: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 9b95233..ae29f30d 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1286,6 +1286,7 @@ static int gen8_emit_flush_render(struct intel_ringbuffer *ringbuf,
 	struct intel_engine_cs *ring = ringbuf->ring;
 	u32 scratch_addr = ring->scratch.gtt_offset + 2 * CACHELINE_BYTES;
 	u32 flags = 0;
+	int ret;
 
 	flags |= PIPE_CONTROL_CS_STALL;
 
@@ -1303,6 +1304,15 @@ static int gen8_emit_flush_render(struct intel_ringbuffer *ringbuf,
 		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(ringbuf, flags, scratch_addr);
-- 
1.9.3