I think I may have gathered a useful clue, though of the kind I was expecting...
In order to gather the boot messages immediately before shutdown, that I don't normally get to see due to the graphics card output turning off early, I attached to the Linux console via serial, by adding this on the linux kernel command line: console=ttyS0,38400 After doing that, for about seven boots, I couldn't reproduce the original problem. I removed that option again for a couple of boot-shutdown cycles, and on the second one on shutdown it failed to power the machine off again. I also tried reinstating the 'quiet' option to the kernel which is there by default after installing Debian, and shutdown still failed the next time. Put the console=ttyS0,38400 back, and the problem *seems* to go away. However the failed poweroff is intermittent, so the use of console=ttyS0,38400 and it consistently powering off OK could just be happy coincidence. I intend to keep the linux console as serial for a few days, and see if I or the machine's other user experiences this poweroff problem again under normal operation rather than my forced idea of normal operation. If it's consistently OK for that time, I think it would be safe to say that this bug only appears for me if the console is the graphics card. It also appears that the display stayed on with a blinking cursor in the top left right until poweroff, whereas without that option it turned off earlier. For the record at this point, I think it's worth mentioning that my graphics adapter is: 01:00.0 VGA compatible controller [0300]: NVIDIA Corporation G98 [GeForce 8400 GS Rev. 2] [10de:06e4] (rev a1) and it's being driven with the nouveau graphics driver. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
