Hi Rafael,
On 16 September 2016 at 00:44, Rafael Antognolli rafael.antognolli@intel.com wrote:
When we merge several fences, if all of them are signaled already, we still keep one of them. So instead of using add_fence(), which will not increase the refcount of signaled fences, we should explicitly call fence_get() for the fence we are keeping.
This patch fixes a kernel panic that can be triggered by creating a fence that is expired (or increasing the timeline until it expires), then creating a merged fence out of it, and deleting the merged fence. This will make the original expired fence's refcount go to zero.
Testcase: igt/sw_sync/sync_expired_merge Signed-off-by: Rafael Antognolli rafael.antognolli@intel.com Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Gustavo Padovan gustavo.padovan@collabora.co.uk
Thanks for the patch; applied via drm-misc.
drivers/dma-buf/sync_file.c | 6 ++----
Best, Sumit.