[PATCH] drm/i915/gvt: set the correct default value of CTX STATUS PTR

[Zhenyu Wang]

From: Min He <min.he at intel.com>

Fix wrong initial csb read pointer value. This fixes the random
engine timeout issue in guest when guest boots up.

Cc: stable at vger.kernel.org # v4.10+
Signed-off-by: Min He <min.he at intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
---
 drivers/gpu/drm/i915/gvt/execlist.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/execlist.c b/drivers/gpu/drm/i915/gvt/execlist.c
index ce4276a7cf9c..536bde8638c8 100644
--- a/drivers/gpu/drm/i915/gvt/execlist.c
+++ b/drivers/gpu/drm/i915/gvt/execlist.c
@@ -776,7 +776,8 @@ static void init_vgpu_execlist(struct intel_vgpu *vgpu, int ring_id)
 			_EL_OFFSET_STATUS_PTR);
 
 	ctx_status_ptr.dw = vgpu_vreg(vgpu, ctx_status_ptr_reg);
-	ctx_status_ptr.read_ptr = ctx_status_ptr.write_ptr = 0x7;
+	ctx_status_ptr.read_ptr = 0;
+	ctx_status_ptr.write_ptr = 0x7;
 	vgpu_vreg(vgpu, ctx_status_ptr_reg) = ctx_status_ptr.dw;
 }
 
-- 
2.11.0