On Tue, Mar 29, 2016 at 06:44:57PM +0200, Florian Zumbiehl wrote: > Hi, > > > FBDEV_EMULATION vs. I915_FBDEV is probably a read herring, more likely is > > that for some odd reason the very first modeset fails. Once X has > > resurrect the screen, can you then switch to fbcon? Also please check in > > /sys/class/vtconsole whether the fbdev driver is loaded and bound (check > > the name and bind files). And make sure there's that dmesg still says it > > initialized the "inteldrmfb" driver. > > Trying to collect that information actually solved the problem: fbcon > didn't actually get loaded during boot, only the graphics drivers, which > caused the screen to go blank, loading fbcon happened only when starting > the X server ... seems weird to me, but I guess there is some non-obvious > logic behind that, and in any case it seems to be a change in behaviour. > Well, thanks for the pointer anyway, I guess! ;-) > > Now, while at it: I also have a bunch of WARN_ONs and ERRORs happening (the > former primarily when an Xv window disappears from the screen, it seems, > the latter primarily during boot), which don't seem to have any immediate > negative effects at the surface, like this: > > | [ 14.815467] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun > | [ 14.815642] [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* pipe B underrun > | [ 14.815806] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun > | [ 14.823686] [drm] initialized overlay support > | [ 14.873165] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun We've fixed piles of those in recent kernels, but didn't backport all the fixes (since usually it's a silent failure, but it can correlate with black screens). > | [ 2520.457732] WARNING: CPU: 0 PID: 3193 at drivers/gpu/drm/i915/i915_gem.c:4508 i915_gem_free_object+0x277/0x280 [i915]() > | [ 2520.457736] WARN_ON(obj->frontbuffer_bits) Hm, this one should be fixed, and the patches should all be correctly marked for stable. Either there's a backlog somewhere, or we failed. Would be great if you can test a drm-intel-nightly build (or 4.6-rc1) for either and confirm that they're gone. And for the later we really should hunt down the bugfix if it's stuck. > Also, I have occasional X server crashes (every few weeks or so) which > started with 4.1.9, I think (I had 3.11.0 before that), and I had some kind > of problem with Xv not working anymore until reboot with 4.1.9 which hasn't > happened with 4.4.5 yet ... do you think any of those would be worth > further investigation? If so, any suggestions as to how to split it all > into separate issues/how to go about it? No idea about X stuff, not my expertise ;-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
