On 3/29/2016 11:49 PM, Michel Dänzer wrote: > On 29.03.2016 18:55, Julian Margetson wrote: >> On 3/28/2016 11:15 PM, Michel Dänzer wrote: >>> On 29.03.2016 08:47, Julian Margetson wrote: >>>> Seeing the following when booting kernel 4.6-rc1 on Acube Sam460ex >>>> Canyonlands board. >>>> This loops for a few times then the kernel boots. >>>> No problem with the 4.6-rc1 with an A-eon Tabor Freescale e500v2 board. >>>> >>>> Regards >>>> >>>> Julian >>>> >>>> >>>> [ 2.197839] ------------[ cut here ]------------ >>>> [ 2.197850] WARNING: CPU: 0 PID: 1 at >>>> drivers/gpu/drm/drm_irq.c:1368 drm_vblank_off+0x2c/0x1e0 >>> That's >>> >>> if (WARN_ON(pipe >= dev->num_crtcs)) >>> >>> My best guess is that drm_vblank_off is called before drm_vblank_init, >>> so dev->num_crtcs is still 0. >>> >>> >>> Please provide the full dmesg output corresponding to the problem. >>> >>> >> Attached > [...] > >> [drm] radeon: irq initialized. >> [drm:r600_ring_test] *ERROR* radeon: ring 0 test failed >> (scratch(0x850C)=0xCAFEDEAD) >> radeon 0001:81:00.0: disabling GPU acceleration > Okay, so the problem is that acceleration fails to initialize, in which > case the driver calls drm_vblank_cleanup. > > I can see two basic options for a solution: Either don't call > radeon_irq_kms_fini/drm_vblank_cleanup if acceleration fails to > initialize, or check if acceleration is enabled before calling > drm_vblank_on/off. Any preferences? > > Thanks
No preferences . I would be interested in a fix for the acceleration problem if possible . I am willing to test to try to determine the exact cause if you would direct me . Regards Julian
