I have a Macbook 15" Pro 8.2
Which apparently is supposed to be switchable between the GFX cards with vgaswitcheroo. But /sys/kernel/debug/ contains no switcheroo folder.
syslog gives me this.
[ 21.631041] vga_switcheroo: enabled [ 21.631075] radeon 0000:01:00.0: Invalid ROM contents [ 21.631149] radeon 0000:01:00.0: Invalid ROM contents [ 21.631154] [drm:radeon_get_bios] *ERROR* Unable to locate a BIOS ROM [ 21.631163] radeon 0000:01:00.0: Fatal error during GPU init [ 21.631165] [drm] radeon: finishing device. [ 21.631166] [TTM] Memory type 2 has not been initialized [ 21.632193] radeon 0000:01:00.0: no bo for sa manager [ 21.632197] vga_switcheroo: disabled
it seems that it tries to enable it but then fails. In other faqs on the net i hear that when booting in efi mode there is no bios. And because of this the ati card cant initialize properly. Sounds like it could be the reason. Anyone know how to load the bios rom when in efi mode?
--ok some updates-- There is a patch that works. Allowing the loading of the video bios from a file for the 3.4 kernel.
These features have been merged into 3.6-rc 3 apparently. But I'm on that kernel and still cant switch over to the ATI card.
apparently others have the same issue