Created attachment 215501 [details] output of lspci -vvv I use Debian testing on Asus X751M laptop, and at random moments the system just hangs so I have to reboot it by holding the power button. The Fn buttons stop working too, and the sound also stops. I tried pressing AltSysRq+R, then Alt+SysRq+B, but it does not work (it does work before the system hangs). I configured journald to write logs to disk, but after the hang there is nothing additional to what the kernel has printed before it. I have compiled the 4.6-rc6 kernel, but it did not help. I also have a graphics issue, but I don't know if it is related. I will report it as a separate bug and post a link.
Reported the graphics issue as https://bugs.freedesktop.org/show_bug.cgi?id=94605#c7 It seems to be unrelated, as the screen does not go black on 4.4.0, but the hang still occurs.
4.6 hangs too. This time I had a watchdog set up, but it just shut my machine down instead of rebooting it. If I manually "time out" the watchdog, it reboots the machine normally. Any advises how to track it down?