Awesome, thanks, it is EXTREMELY useful | Find the right one and denylist it. One more question: how do I 'denylist' the offending alias?
Thanks Vadim On Thu, Nov 17, 2022 at 3:22 PM Lennart Poettering <lenn...@poettering.net> wrote: > On Mi, 16.11.22 10:24, Vadim Lebedev (vadiml1...@gmail.com) wrote: > > > I'm preparing ubuntu-based live boot disk. It works fine mostly, but on > > some machines equipped with Nvidia Quadro cards the default nouveau > driver > > causes problems (temporary freezes). I've determined that buy > blacklisting > > nouveau driver (in /etc/modprobe.d/blacklist.conf) I can fix the problem. > > However this approach inhibits nouveau driver for every nvidia equipped > > machine which is an overkill. Of course, i can detect the presence of the > > Quadro card after the boot, blacklist it, do update-initramfs -u and > reboot > > but this approach modifies live boot disk and I would like to avoid > that. I > > wonder if there is a way to detect the presence of nvidia Quadro > somewhere > > very early in the boot sequence and prevent loading of the offending > driver > > and fall back to standard VESA driver. > > PCI drivers are loaded via a "modalias" string, which is synthesized > from the PCI and USB vendor and product IDs (and other PCI > info). Drivers declare in their kmod metadata which of these modalias > strings they want to be responsible for. > > Do "modinfo nouveau" for example, which will show you this > information: > > <snip> > … > alias: pci:v000012D2d*sv*sd*bc03sc*i* > alias: pci:v000010DEd*sv*sd*bc03sc*i* > … > </snip> > > The "*" are wildcard expressions. > > Now, the kernel will never ask userspace for the "nouveau" driver but > only for a driver for such a modalias string. > > You can denylist that string for your hw and thus disable the > autoloading. > > Use "grep . /sys/bus/*/*/*/modalias" to get a list of the actual > modalias strings requested on your system. The one nuveau.ko matched > against will be among them. Find the right one and denylist it. > > Lennart > > -- > Lennart Poettering, Berlin >
