#0  0x00007fb9e1b06afc in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fb9dd3a25f5 in cnd_wait (cond=0x55bd80344b70, mtx=0x55bd80344b48) at ../include/c11/threads_posix.h:155
#2  0x00007fb9dd3a2be3 in pipe_semaphore_wait (sema=0x55bd80344b48) at ../src/gallium/auxiliary/os/os_thread.h:108
#3  0x00007fb9dd3a4937 in lp_rast_finish (rast=0x55bd80344a30) at ../src/gallium/drivers/llvmpipe/lp_rast.c:770
#4  0x00007fb9dd3b76cc in lp_setup_rasterize_scene (setup=0x55bd803838f0) at ../src/gallium/drivers/llvmpipe/lp_setup.c:181
#5  0x00007fb9dd3b7bc6 in set_scene_state
    (setup=0x55bd803838f0, new_state=SETUP_FLUSHED, reason=0x7fb9ddf7af80 <__func__.17956> "do_flush")
    at ../src/gallium/drivers/llvmpipe/lp_setup.c:331
#6  0x00007fb9dd3b7cac in lp_setup_flush (setup=0x55bd803838f0, fence=0x0, reason=0x7fb9ddf7af80 <__func__.17956> "do_flush")
    at ../src/gallium/drivers/llvmpipe/lp_setup.c:360
#7  0x00007fb9dd39fe08 in llvmpipe_flush (pipe=0x55bd8035a330, fence=0x0, reason=0x7fb9ddf7af80 <__func__.17956> "do_flush")
    at ../src/gallium/drivers/llvmpipe/lp_flush.c:56
#8  0x00007fb9dd39ede9 in do_flush (pipe=0x55bd8035a330, fence=0x0, flags=1)
    at ../src/gallium/drivers/llvmpipe/lp_context.c:117
#9  0x00007fb9ddaec60c in st_flush (st=0x55bd8052a000, fence=0x0, flags=1) at ../src/mesa/state_tracker/st_cb_flush.c:55
#10 0x00007fb9dd9a6f88 in st_context_flush (stctxi=0x55bd8052a000, flags=2, fence=0x0)
    at ../src/mesa/state_tracker/st_manager.c:653
#11 0x00007fb9dd2be60a in dri_flush (cPriv=0x55bd80355840, dPriv=0x55bd809b1820, flags=5, reason=__DRI2_THROTTLE_SWAPBUFFER)
    at ../src/gallium/state_trackers/dri/dri_drawable.c:581
#12 0x00007fb9e031fc25 in dri2_flush_drawable_for_swapbuffers (disp=0x55bd80358b10, draw=0x55bd809b1e30)
    at ../src/egl/drivers/dri2/egl_dri2.c:1647
#13 0x00007fb9e0328de1 in dri2_drm_swap_buffers (drv=0x55bd80356a80, disp=0x55bd80358b10, draw=0x55bd809b1e30)
    at ../src/egl/drivers/dri2/platform_drm.c:452
#14 0x00007fb9e031fcad in dri2_swap_buffers (drv=0x55bd80356a80, dpy=0x55bd80358b10, surf=0x55bd809b1e30)
    at ../src/egl/drivers/dri2/egl_dri2.c:1666
#15 0x00007fb9e03110c0 in eglSwapBuffers (dpy=0x55bd80358b10, surface=0x55bd809b1e30) at ../src/egl/main/eglapi.c:1275
#16 0x00007fb9e1f8ffcb in wlr_egl_swap_buffers (egl=0x55bd802fda78, surface=0x55bd809b1e30, damage=damage@entry=0x0)
    at ../render/egl.c:344
#17 0x00007fb9e1f85233 in swap_drm_surface_buffers (surf=surf@entry=0x55bd802ebce0, damage=damage@entry=0x0)
    at ../backend/drm/renderer.c:136
#18 0x00007fb9e1f852e8 in get_drm_surface_front (surf=0x55bd802ebce0) at ../backend/drm/renderer.c:153
--Type <RET> for more, q to quit, c to continue without paging--
#19 0x00007fb9e1f8145b in drm_connector_start_renderer (conn=0x55bd8053b090) at ../backend/drm/drm.c:367
#20 0x00007fb9e1f82c48 in drm_connector_start_renderer (conn=0x55bd8053b090) at ../backend/drm/drm.c:515
#21 0x00007fb9e1f82c48 in drm_connector_set_mode (output=0x55bd8053b090, mode=0x55bd809b1300) at ../backend/drm/drm.c:524
#22 0x000055bd7f4bfda6 in apply_output_config (oc=0x0, output=0x55bd809b1b20) at ../sway/config/output.c:206
#23 0x000055bd7f4e0810 in output_enable (output=0x55bd809b1b20, oc=0x0) at ../sway/tree/output.c:69
#24 0x000055bd7f4ad247 in handle_new_output (listener=0x55bd7f4ffb58 <server+56>, data=0x55bd8053b090)
    at ../sway/desktop/output.c:564
#25 0x00007fb9e1fb7ebe in wlr_signal_emit_safe (signal=0x55bd802e1b38, data=0x55bd8053b090) at ../util/signal.c:29
#26 0x00007fb9e1fb7ebe in wlr_signal_emit_safe (signal=signal@entry=0x55bd802fd988, data=data@entry=0x55bd8053b090)
    at ../util/signal.c:29
#27 0x00007fb9e1f84015 in scan_drm_connectors (drm=<optimized out>) at ../backend/drm/drm.c:1211
#28 0x00007fb9e1f80f73 in backend_start (backend=<optimized out>) at ../backend/drm/backend.c:26
#29 0x00007fb9e1f8a156 in multi_backend_start (wlr_backend=0x55bd802e1b10) at ../backend/multi/backend.c:31
#30 0x000055bd7f4a98fb in server_start_backend (server=0x55bd7f4ffb20 <server>) at ../sway/server.c:176
#31 0x000055bd7f4a8ed0 in main (argc=4, argv=0x7fff8eb9c2f8) at ../sway/main.c:378