On May 05 Zanoni, Paulo R wrote: > Em Qui, 2016-05-05 às 19:45 +0200, Stefan Richter escreveu: > > Oh, and in case you - the person reading this commit message - found > > this commit through git bisect, please do the following: > > - Check your dmesg and see if there are error messages mentioning > > underruns around the time your problem started happening. > > > > Well, I always had the followings lines in dmesg: > > [drm:intel_set_cpu_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A > > [drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun > > Oh, well... I had a patch that would just disable FBC in case we saw a > FIFO underrun, but it was rejected. Maybe this is the time to think > about it again? Otherwise, I can't think of much besides disabling FBC > on HSW until all the underruns and watermarks regressions are fixed > forever. Just to be clear though, I know that these messages are emitted when the monitor is switched on, and when sddm is being shut down --- but I do not know whether there is any sort of underrun when I get the FBC related freeze (since I just don't get any kernel messages at that point). Is there a chance that a serial console would fare better than netconsole? This board and another PC in its vicinity have got onboard serial ports but I don't have cables at the moment. > > - Download intel-gpu-tools, compile it, and run: > > $ sudo ./tests/kms_frontbuffer_tracking --run-subtest '*fbc-*' 2>&1 | tee fbc.txt > > Then send us the fbc.txt file, especially if you get a failure. > > This will really maximize your chances of getting the bug fixed > > quickly. > > > > Do you need this while FBC is enabled, or can I run it while FBC is > > disabled? > > FBC enabled. Considering your description, my hope is that maybe some > specific subtest will be able to hang your machine, so testing this > again will require only running the specific subtest instead of waiting > 18 hours. The kms_frontbuffer_tracking runs from which I posted output two hours ago did not trigger a lockup. (I ran them while X11 was shut down because otherwise kms_frontbuffer_tracking would skip all tests with "Can't become DRM master, please check if no other DRM client is running.") > > PS: > > I am mentioning the following just in case that it has any relationship > > with the FBC related kernel freezes. Maybe it doesn't... There is > > another recent regression on this PC, but I have not yet figured out > > whether it was introduced by any particular kernel version. The > > regression is: When switching from X11 to text console by [Ctrl][Alt][Fx] > > or by shutting down sddm, I often only get a blank screen. I suspect > > that this regression was introduced when I replaced kdm by sddm, but > > I am not sure about that. > > Maybe there is some relationship, since this operation involves a mode > change. You can also try checking dmesg to see if there are underruns > right when you do the change. Yes, this is accompanied by [drm:intel_set_cpu_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A [drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun -- Stefan Richter -======----- -=-= --=-= http://arcgraph.de/sr/ _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
