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charset="utf-8" From: Rob Clark This resolves a potential deadlock vs msm_gem_vm_close(). Otherwise for _NO_SHARE buffers msm_gem_describe() could be trying to acquire the shared vm resv, while already holding priv->obj_lock. But _vm_close() might drop the last reference to a GEM obj while already holding the vm resv, and msm_gem_free_object() needs to grab priv->obj_lock, a locking inversion. OTOH this is only for debugfs and it isn't critical if we undercount by skipping a locked obj. So just use trylock() and move along if we can't get the lock. Signed-off-by: Rob Clark Signed-off-by: Rob Clark Tested-by: Antonino Maniscalco Reviewed-by: Antonino Maniscalco --- drivers/gpu/drm/msm/msm_gem.c | 3 ++- drivers/gpu/drm/msm/msm_gem.h | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index e3ccda777ef3..3e87d27dfcb6 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -938,7 +938,8 @@ void msm_gem_describe(struct drm_gem_object *obj, struc= t seq_file *m, uint64_t off =3D drm_vma_node_start(&obj->vma_node); const char *madv; =20 - msm_gem_lock(obj); + if (!msm_gem_trylock(obj)) + return; =20 stats->all.count++; stats->all.size +=3D obj->size; diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index ce5e90ba935b..1ce97f8a30bb 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -280,6 +280,12 @@ msm_gem_lock(struct drm_gem_object *obj) dma_resv_lock(obj->resv, NULL); } =20 +static inline bool __must_check +msm_gem_trylock(struct drm_gem_object *obj) +{ + return dma_resv_trylock(obj->resv); +} + static inline int msm_gem_lock_interruptible(struct drm_gem_object *obj) { --=20 2.50.0