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>

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 3c38ea4..305a657 100644 (file)
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -2438,6 +2438,12 @@ static u32 evergreen_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;
 }
 

diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 7cead76..d4c633e 100644 (file)
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -1381,6 +1381,12 @@ static u32 cayman_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;
 }
 

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 6d4b561..0740db3 100644 (file)
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1394,6 +1394,12 @@ static u32 r600_gpu_check_soft_reset(struct radeon_device *rdev)
        if (r600_is_display_hung(rdev))
                reset_mask |= RADEON_RESET_DISPLAY;
 
+       /* 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;
 }
 

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 80979ed..9128120 100644 (file)
--- 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;
 }