Introducing more usage of dma-fence-chain and dma-fence-array in the i915 driver we start to hit lockdep splats due to the recursive fence locking in the dma-fence-chain and dma-fence-array containers. This is a humble suggestion to try to establish a dma-fence locking order (patch 1) and to avoid excessive recursive locking in these containers (patch 2)
Thomas Hellström (2): dma-fence: Avoid establishing a locking order between fence classes dma-fence: Avoid excessive recursive fence locking from enable_signaling() callbacks
drivers/dma-buf/dma-fence-array.c | 23 +++++++-- drivers/dma-buf/dma-fence-chain.c | 12 ++++- drivers/dma-buf/dma-fence.c | 79 +++++++++++++++++++++---------- include/linux/dma-fence.h | 4 ++ 4 files changed, 89 insertions(+), 29 deletions(-)
Cc: linaro-mm-sig@lists.linaro.org Cc: dri-devel@lists.freedesktop.org Cc: Christian König christian.koenig@amd.com