drm/radeon: skip MC reset as it's probably not hung

The MC is mostly likely busy (e.g., display requests), not hung
so no need to reset it.  Doing an MC reset is tricky and not
particularly reliable.  Fixes hangs in certain cases.

Reported-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 80979ed951eb..9128120da044 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -2284,6 +2284,12 @@ static u32 si_gpu_check_soft_reset(struct radeon_device *rdev)
         if (tmp & L2_BUSY)
                 reset_mask |= RADEON_RESET_VMC;
 
+        /* Skip MC reset as it's mostly likely not hung, just busy */
+        if (reset_mask & RADEON_RESET_MC) {
+                DRM_DEBUG("MC busy: 0x%08X, clearing.\n", reset_mask);
+                reset_mask &= ~RADEON_RESET_MC;
+        }
+
         return reset_mask;
 }