Post A9iiPyqFQW9mgkmXr6 by roxie@fedi.queerdorks.club
 (DIR) More posts by roxie@fedi.queerdorks.club
 (DIR) Post #A9igTCE3vCND9vKJk0 by roxie@fedi.queerdorks.club
       2021-07-27T15:14:33Z
       
       0 likes, 2 repeats
       
       Need tech help. I have two GPUs in my motherboard. The motherboard keeps selecting the wrong GPU as the one to output to. In Linux I can't find any settings to make the os use the correct GPU. Anytime I search for this it ends up being an integrated vs dedicated thing. Butni have two dedicated cards. I need the PC to only use one since the other will be passed to vfio
       
 (DIR) Post #A9igTCcWSFwINmlqro by seasharp@crowsnest.libre.audio
       2021-07-27T16:34:48.558821Z
       
       0 likes, 0 repeats
       
       @roxie https://forums.centos.org/viewtopic.php?t=60531I would higjly reccomend looking into what's called a 'pci-stub' - its basically a way to tell the kernel to immediately park a PCI device with a dummy driver so it can be safely detached and reattached after the system has fully booted.This is useful when you need the system to stay hands-off with a particular device like a GPU until you're fully booted and ready for something like vfio to pick it up (which I presume is for PCI paasthrough in your case - as it was for me)If you're using UEFI to boot you may also need `dracut` to help you rebuild the init ramdisk to prevent the GPU driver from being loaded when the init image is passed to the kernel.If you have any questions feel free to ask - it can take a while to grasp how it all fits together and my explanation may not convey the useful bits effectively for you.
       
 (DIR) Post #A9ihBjlWaCg5vFDWim by NHG@soc.nhg.moe
       2021-07-27T16:42:53.056636Z
       
       0 likes, 0 repeats
       
       @roxie check if the bios/uefi has an option to select the primary gpu
       
 (DIR) Post #A9ihODGmiFzCu2muGW by roxie@fedi.queerdorks.club
       2021-07-27T16:39:38Z
       
       0 likes, 0 repeats
       
       @seasharp would this take effect like when booting so that I could see grub and input a password for my root drive? All before the actual kernal loads but like its the ramfs kernal thingy
       
 (DIR) Post #A9ihODqaZ8csh5XV4a by seasharp@crowsnest.libre.audio
       2021-07-27T16:45:07.249620Z
       
       0 likes, 0 repeats
       
       @roxie Oh that's a good question - I think you'd need to tell grub which output to use separately from the kernel. There might be a grub2-mkconfig option for that I would expect.
       
 (DIR) Post #A9ii5d7IURw7WB3LDk by roxie@fedi.queerdorks.club
       2021-07-27T16:48:08Z
       
       0 likes, 0 repeats
       
       @NHG nope
       
 (DIR) Post #A9ii5dZIoKL0v29hs8 by NHG@soc.nhg.moe
       2021-07-27T16:52:58.041912Z
       
       0 likes, 0 repeats
       
       @roxie i have options vfio-pci ids=10de:1b80,10de:10f0 disable_vga=1 in /etc/modprobe.d/vfio.conf, maybe thats enough? (pcie ids are the gpu and its sound chip that i pass through) but i don't use the host os anyways so i just blacklisted all the gpu drivers aswell
       
 (DIR) Post #A9iiPyqFQW9mgkmXr6 by roxie@fedi.queerdorks.club
       2021-07-27T16:49:06Z
       
       1 likes, 0 repeats
       
       @seasharp that might be worth a shout. I just need to know what the password entry uses and if its still "grub" and then once it unlocks like then the kernal will do the rest
       
 (DIR) Post #A9iiXENQ4ATkteksOe by seasharp@crowsnest.libre.audio
       2021-07-27T16:57:58.117568Z
       
       0 likes, 0 repeats
       
       @roxie for sure! Worst case you're punching your root drive decryption passphrase in using the second monitor but after that the kernel and the stub driver should do the rest, as you said.Good luck :)