On 08.02.23 09:48, Chris Clayton wrote: > > I'm assuming that we are not going to see a fix for this regression before 6.2 is released. Yeah, looks like it. That's unfortunate, but happens. But there is still time to fix it and there is one thing I wonder: Did any of the nouveau developers look at the netconsole captures Chris posted more than a week ago to check if they somehow help to track down the root of this problem? Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page. > Consequently, I've > implemented a (very simple) workaround. All that happens is that in the (sysv) init script that starts and stops SDDM, > the nouveau module is removed once SDDM is stopped. With that in place, my system no longer freezes on reboot or poweroff. > > Let me know if I can provide any additional diagnostics although, with the problem seemingly occurring so late in the > shutdown process, I may need help on how to go about capturing. > > Chris > > On 02/02/2023 20:45, Chris Clayton wrote: >> >> >> On 01/02/2023 13:51, Chris Clayton wrote: >>> >>> >>> On 30/01/2023 23:27, Ben Skeggs wrote: >>>> On Tue, 31 Jan 2023 at 09:09, Chris Clayton <chris2553@xxxxxxxxxxxxxx> wrote: >>>>> >>>>> Hi again. >>>>> >>>>> On 30/01/2023 20:19, Chris Clayton wrote: >>>>>> Thanks, Ben. >>>>> >>>>> <snip> >>>>> >>>>>>> Hey, >>>>>>> >>>>>>> This is a complete shot-in-the-dark, as I don't see this behaviour on >>>>>>> *any* of my boards. Could you try the attached patch please? >>>>>> >>>>>> Unfortunately, the patch made no difference. >>>>>> >>>>>> I've been looking at how the graphics on my laptop is set up, and have a bit of a worry about whether the firmware might >>>>>> be playing a part in this problem. In order to offload video decoding to the NVidia TU117 GPU, it seems the scrubber >>>>>> firmware must be available, but as far as I know,that has not been released by NVidia. To get it to work, I followed >>>>>> what ubuntu have done and the scrubber in /lib/firmware/nvidia/tu117/nvdec/ is a symlink to >>>>>> ../../tu116/nvdev/scrubber.bin. That, of course, means that some of the firmware loaded is for a different card is being >>>>>> loaded. I note that processing related to firmware is being changed in the patch. Might my set up be at the root of my >>>>>> problem? >>>>>> >>>>>> I'll have a fiddle an see what I can work out. >>>>>> >>>>>> Chris >>>>>> >>>>>>> >>>>>>> Thanks, >>>>>>> Ben. >>>>>>> >>>>>>>> >>>>> >>>>> Well, my fiddling has got my system rebooting and shutting down successfully again. I found that if I delete the symlink >>>>> to the scrubber firmware, reboot and shutdown work again. There are however, a number of other files in the tu117 >>>>> firmware directory tree that that are symlinks to actual files in its tu116 counterpart. So I deleted all of those too. >>>>> Unfortunately, the absence of one or more of those symlinks causes Xorg to fail to start. I've reinstated all the links >>>>> except scrubber and I now have a system that works as it did until I tried to run a kernel that includes the bad commit >>>>> I identified in my bisection. That includes offloading video decoding to the NVidia card, so what ever I read that said >>>>> the scrubber firmware was needed seems to have been wrong. I get a new message that (nouveau 0000:01:00.0: fb: VPR >>>>> locked, but no scrubber binary!), but, hey, we can't have everything. >>>>> >>>>> If you still want to get to the bottom of this, let me know what you need me to provide and I'll do my best. I suspect >>>>> you might want to because there will a n awful lot of Ubuntu-based systems out there with that scrubber.bin symlink in >>>>> place. On the other hand,m it could but quite a while before ubuntu are deploying 6.2 or later kernels. >>>> The symlinks are correct - whole groups of GPUs share the same FW, and >>>> we use symlinks in linux-firmware to represent this. >>>> >>>> I don't really have any ideas how/why this patch causes issues with >>>> shutdown - it's a path that only gets executed during initialisation. >>>> Can you try and capture the kernel log during shutdown ("dmesg -w" >>>> over ssh? netconsole?), and see if there's any relevant messages >>>> providing a hint at what's going on? Alternatively, you could try >>>> unloading the module (you will have to stop X/wayland/gdm/etc/etc >>>> first) and seeing if that hangs too. >>>> >>>> Ben. >>> >>> Sorry for the delay - I've been learning about netconsole and netcat. However, I had no success with ssh and netconsole >>> produced a log with nothing unusual in it. >>> >>> Simply stopping Xorg and removing the nouveau module succeeds. >>> >>> So, I rebuilt rc6+ after a pull from linus' tree this morning and set the nouveau debug level to 7. I then booted to a >>> console before doing a reboot (with Ctl+Alt+Del). As expected the machine locked up just before it would ordinarily >>> restart. The last few lines on the console might be helpful: >>> >>> ... >>> nouveau 0000:01:00:0 fifo: preinit running... >>> nouveau 0000:01:00:0 fifo: preinit completed in 4us >>> nouveau 0000:01:00:0 gr: preinit running... >>> nouveau 0000:01:00:0 gr: preinit completed in 0us >>> nouveau 0000:01:00:0 nvdec0: preinit running... >>> nouveau 0000:01:00:0 nvdec0: preinit completed in 0us >>> nouveau 0000:01:00:0 nvdec0: preinit running... >>> nouveau 0000:01:00:0 nvdec0: preinit completed in 0us >>> nouveau 0000:01:00:0 sec2: preinit running... >>> nouveau 0000:01:00:0 sec2: preinit completed in 0us >>> nouveau 0000:01:00:0 fb:.VPR locked, running scrubber binary >>> >>> These messages appear after the "sd 4:0:0:0 [sda] Stopping disk" I reported in my initial email. >>> >>> After the "running scrubber" line appears the machine is locked and I have to hold down the power button to recover. I >>> get the same outcome from running "halt -dip", "poweroff -di" and "shutdown -h -P now". I guess it's no surprise that >>> all three result in the same outcome because invocations halt, poweroff and reboot (without the -f argument)from a >>> runlevel other than 0 resukt in shutdown being run. switching to runlevel 0 with "telenit 0" results in the same >>> messages from nouveau followed by the lockup. >>> >>> Let me know if you need any additional diagnostics. >>> >>> Chris >>> >> >> I've done some more investigation and found that I hadn't done sufficient amemdment the scripts run at shutdown to >> prevent the network being shutdown. I've now got netconsole captures for 6.2.0-rc6+ >> (9f266ccaa2f5228bfe67ad58a94ca4e0109b954a) and, for comparison, 6.1.9. These two logs are attached. >> >> Chris >> >>>> >>>>> >>>>> Thanks, >>>>> >>>>> Chris >>>>> >>>>> <snip> > >
