drm/amdgpu: enable mcbp by default on gfx9

It's required for high priority queues.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2535
Reviewed-and-tested-by: Jiadong Zhu <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: alexdeucher

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -3678,6 +3678,11 @@ static void amdgpu_device_set_mcbp(struct amdgpu_device *adev)
 	if (amdgpu_mcbp == 1)
 		adev->gfx.mcbp = true;
 
+	if ((adev->ip_versions[GC_HWIP][0] >= IP_VERSION(9, 0, 0)) &&
+	    (adev->ip_versions[GC_HWIP][0] < IP_VERSION(10, 0, 0)) &&
+	    adev->gfx.num_gfx_rings)
+		adev->gfx.mcbp = true;
+
 	if (amdgpu_sriov_vf(adev))
 		adev->gfx.mcbp = true;
 

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -180,7 +180,7 @@ uint amdgpu_dc_feature_mask = 2;
 uint amdgpu_dc_debug_mask;
 uint amdgpu_dc_visual_confirm;
 int amdgpu_async_gfx_ring = 1;
-int amdgpu_mcbp;
+int amdgpu_mcbp = -1;
 int amdgpu_discovery = -1;
 int amdgpu_mes;
 int amdgpu_mes_kiq;
@@ -634,10 +634,10 @@ module_param_named(async_gfx_ring, amdgpu_async_gfx_ring, int, 0444);
 
 /**
  * DOC: mcbp (int)
- * It is used to enable mid command buffer preemption. (0 = disabled (default), 1 = enabled)
+ * It is used to enable mid command buffer preemption. (0 = disabled, 1 = enabled, -1 auto (default))
  */
 MODULE_PARM_DESC(mcbp,
-	"Enable Mid-command buffer preemption (0 = disabled (default), 1 = enabled)");
+	"Enable Mid-command buffer preemption (0 = disabled, 1 = enabled), -1 = auto (default)");
 module_param_named(mcbp, amdgpu_mcbp, int, 0444);
 
 /**