It is possible for a BO to exist that is not currently associated with a
resource, e.g. because it has been evicted.

When devcoredump tries to read the contents of all BOs for dumping, we need
to expect this as well -- in this case, ENODATA is recorded instead of the
buffer contents.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6271
Signed-off-by: Simon Richter <[email protected]>
---
 drivers/gpu/drm/ttm/ttm_bo_vm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index b47020fca199..a101ff95b234 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -434,6 +434,12 @@ int ttm_bo_access(struct ttm_buffer_object *bo, unsigned 
long offset,
        if (ret)
                return ret;
 
+       if (!bo->resource) {
+               ret = -ENODATA;
+               goto unlock;
+       }
+
        switch (bo->resource->mem_type) {
        case TTM_PL_SYSTEM:
                fallthrough;
@@ -448,6 +454,7 @@ int ttm_bo_access(struct ttm_buffer_object *bo, unsigned 
long offset,
                        ret = -EIO;
        }
 
+unlock:
        ttm_bo_unreserve(bo);
 
        return ret;
-- 
2.47.3

Reply via email to