drm/radeon: Always flush the VM

commit 466476df upstream.

This is slightly cleaned up version of Jerome's patch.
There seems to be an issue tracking the last flush of
the VM which results in hangs in certain cases when
VM is used.  For now just flush the VM for every IB.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=62959
https://bugs.freedesktop.org/show_bug.cgi?id=62997Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/radeon/radeon_ring.c

@@ -180,7 +180,8 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib,
 		radeon_semaphore_free(rdev, &ib->semaphore, NULL);
 	}
 	/* if we can't remember our last VM flush then flush now! */
-	if (ib->vm && !ib->vm->last_flush) {
+	/* XXX figure out why we have to flush for every IB */
+	if (ib->vm /*&& !ib->vm->last_flush*/) {
 		radeon_ring_vm_flush(rdev, ib->ring, ib->vm);
 	}
 	if (const_ib) {