https://bugs.freedesktop.org/show_bug.cgi?id=109102

--- Comment #3 from Gert vd Kraats vd.kraats@hccnet.nl --- I am using intel i915 gen 3 with 16 fence registers. When displaying the variable total_fences at function drm_intel_gem_check_aperture_space at libdrm-2.4.95/intel/intel_bufmgr_gem.c, it is seen that the deadlock-abort is occurring at total_fences == 16, where the previous display shows total_fences == 14, so there is an increment of 2 fences in stead of the usual increment of 1. Apparently the deadlock occurs at the "freeing fences phase", that is started if total_fences is too high. I decided to lower the available_fences from 14 to 13 (see proposed patch). This solved the problem. After this patch I still saw sometimes total_fences == 16, where the previous display shows total_fences == 13, so there is an increment of 3 fences. This did not cause a deadlock at the "freeing fences phase".