Hi Sébastien, Indeed, I had CONFIG_DRM_I915_KMS=y for the integrated gpu, but I was missing CONFIG_DRM_RADEON_KMS=y. After re-compiling the kernel, it now works.
Thanks a lot, Joao ----- Mail original ----- De: "Sebastien Fievet" <sebastien.fie...@free.fr> À: blfs-support@linuxfromscratch.org Envoyé: Samedi 7 Septembre 2013 20:44:40 Objet: Re: [blfs-support] Unable to find vgaswitcheroo to disable discrete gpu On Sat, 7 Sep 2013 12:18:12 +0200 (CEST) joao.more...@free.fr wrote: > Hi all, > > I've built an LFS system on an HP Pavilion laptop, which overheats enormously > due to the high-performance discrete gpu. I'd like to disable it and use only > the low-power integrated gpu. I managed to this under Fedora, by writing > to /sys/kernel/debug/vgaswitcheroo/switch, but I don't have this file under > LFS. > > I had already determined that my 3.2.6 kernel did not have vgaswitcheroo > enabled, so I recompiled it with CONFIG_VGA_SWITCHEROO=y. I also did not have > debugfs mounted, so I added that in /etc/fstab. So now when I boot I see : > > root [ /sys/kernel/debug ]# pwd > /sys/kernel/debug > root [ /sys/kernel/debug ]# ls -l > total 0 > drwxr-xr-x 2 root root 0 Sep 7 2013 acpi > drwxr-xr-x 30 root root 0 Sep 7 2013 bdi > drwxr-xr-x 3 root root 0 Sep 7 2013 boot_params > drwxr-xr-x 4 root root 0 Sep 7 2013 dri > drwxr-xr-x 3 root root 0 Sep 7 2013 hid > drwxr-xr-x 3 root root 0 Sep 7 2013 ieee80211 > drwxr-xr-x 2 root root 0 Sep 7 2013 kprobes > drwxr-xr-x 2 root root 0 Sep 7 2013 mce > -r--r--r-- 1 root root 0 Sep 7 2013 suspend_stats > drwxr-xr-x 5 root root 0 Sep 7 2013 tracing > drwxr-xr-x 6 root root 0 Sep 7 2013 usb > -r--r--r-- 1 root root 0 Sep 7 2013 wakeup_sources > drwxr-xr-x 2 root root 0 Sep 7 2013 x86 > root [ /sys/kernel/debug ]# > > There is no vgaswitcheroo directory. Any idea what's missing ? What do I need > to do more to make it appear ? > > Thanks in advance for your help, > > Joao > -- > http://linuxfromscratch.org/mailman/listinfo/blfs-support > FAQ: http://www.linuxfromscratch.org/blfs/faq.html > Unsubscribe: See the above information page You also need to have KMS enabled drivers (for both iGPU and dGPU). Seb. -- http://linuxfromscratch.org/mailman/listinfo/blfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page -- http://linuxfromscratch.org/mailman/listinfo/blfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
