Re: Disabling drm/ttm/radeon module loading for debugging

On Sun, Jan 24, 2010 at 07:07:22AM +1000, Dave Airlie wrote: > On Sat, 2010-01-23 at 18:49 +0200, Pasi Kärkkäinen wrote: > > On Sat, Jan 23, 2010 at 11:41:15AM -0500, Clyde E. Kunkel wrote: > > > On 01/23/2010 09:08 AM, Pasi Kärkkäinen wrote: > > >> Hello, > > >> > > >> How can I make sure drm/radeon/ttm modules are not loaded, > > >> until I do it manually myself? > > >> > > >> I extracted the initrd image, edited the 'init' script and > > >> commented out loading of the modules, repacked the initrd, > > >> and booted but something (plymouth? udev?) still loads the modules.. > > >> > > >> I'd like to load them later manually, for some debugging purposes.. > > >> > > >> -- Pasi > > >> > > > > > > Try adding nomodeset to the kernel line in grub.conf. > > > > > > > Sorry forgot to mention that I already have nomodeset.. > > It seems it's not enough. > > You should be able to rmmod them with nomodeset, the driver > doesn't do any initialisation in that case. though you > should boot to runlevel 3 as once X starts the hw will > be initialised. > > Then you need to load radeon with modeset=1 to override it. > What I'm trying to do here is to debug some kind of text 'offset' problem when the kernel is booted as Xen dom0, under the hypervisor. I just tried booting the kernel on baremetal, without Xen. It seems something is initialized when the drivers are loaded for the first time (automatically by most probably udev, trying to blacklist them now and see if that prevents them from being loaded), because there's a small 'flash' on the screen when udev is started. This 'flash' happens on baremetal.