drm/amdgpu: disable MCBP by default

Disable MCBP(mid command buffer preemption) by default as old Mesa
hangs with it. We shall not enable the feature that breaks old usermode
driver.

Fixes: 50a7c87 ("drm/amdgpu: enable mcbp by default on gfx9")
Signed-off-by: Jiadong Zhu <Jiadong.Zhu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

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

@@ -3791,10 +3791,6 @@ static void amdgpu_device_set_mcbp(struct amdgpu_device *adev)
 		adev->gfx.mcbp = true;
 	else if (amdgpu_mcbp == 0)
 		adev->gfx.mcbp = false;
-	else if ((amdgpu_ip_version(adev, GC_HWIP, 0) >= IP_VERSION(9, 0, 0)) &&
-		 (amdgpu_ip_version(adev, 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;