Some more investigation, understanding and adding 2 other possible fixes for the problem. The problem occurs at Ubuntu 18.10 only at gdm3 with wayland using dual monitor. It is not occuring with wayland at single monitor. It totally doesnot occur if gdm3 is not using wayland. At ubuntu 18.04 the same problem exists with wayland, but is not occurring so often.
At ubuntu 18.10 with wayland and dual monitor the user session immediately aborts, if 16 or more favorites are allocated at the dock. For some reason wayland seems to use one extra fence register at dual monitor. It is noticed at dual monitor, that gdm3 with wayland uses 2 calls to clutter_stage_cogl_redraw_view for 2 logical screens for every call to clutter_stage_cogl_redraw; gdm3 without wayland does only one call to clutter_stage_cogl_redraw_view for 1 logical screen. The crash occurs at intel_batchbuffer_flush. Always the last batch at such a flush is coming from function emit_copy_blit and intelClearWithBlit at src/mesa/drivers/dri/i915/intel_blit.c. At the call to dri_bufmgr_check_aperture_space they indicate to use zero fence registers, but in fact they use one. This violates the limit of 14, causing a crash at dual monitor. So the call to dri_bufmgr_check_aperture_space must be postponed, until the needed fence register is added in the middle of the batch-generation and then the batch-actions must be undone, a flush is called and batch is regenerated again. For this function intel_batchbuffer_emit_reset is added. This also is done for function intel_miptree_set_alpha_to_one, although I never saw a call of this function. See fix error3_patch2.txt. Another (dirty) solution is to decrement the availablity and just continue. This gives somewhere a failure, but I could not see a failing layout. See fix error3_patch3.txt. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to mesa in Ubuntu. https://bugs.launchpad.net/bugs/1797882 Title: At dual monitor intel_do_flush_locked failed: Resource deadlock avoided To manage notifications about this bug go to: https://bugs.launchpad.net/mesa/+bug/1797882/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
