[Intel-gfx] [PATCH] drm/i915/execlists: WaDisableCtxRestoreArbitration is only needed in gen8

[Michel Thierry]

WaDisableCtxRestoreArbitration was only applied for bdw and chv, but
this changed after the code got moved to gen8_emit_bb_start (and, at
least in my tree, there is no gen9_emit_bb_start).

Fixes: 3ad7b52d962e ("drm/i915/execlists: Move bdw GPGPU w/a to emit_bb")
Signed-off-by: Michel Thierry <michel.thierry at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index c5b76082d695..d2b7eac0777c 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1619,7 +1619,10 @@ static int gen8_emit_bb_start(struct drm_i915_gem_request *req,
 		return PTR_ERR(cs);
 
 	/* WaDisableCtxRestoreArbitration:bdw,chv */
-	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
+	if (IS_GEN8(req->i915))
+		*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
+	else
+		*cs++ = MI_NOOP;
 
 	/* FIXME(BDW): Address space and security selectors. */
 	*cs++ = MI_BATCH_BUFFER_START_GEN8 |
-- 
2.14.1