Tried the branchdrm-nvidia-switch . No way to make vgaswitcheroo work:

both

echo "DDIS" > /sys/kernel/debug/vgaswitcheroo/switch

and

echo "OFF" > /sys/kernel/debug/vgaswitcheroo/switch

hang the machine.

The first command hangs immediately, the second at X restart.

DMESG out in the first case:

Dec 21 22:46:10 daphne kernel: fbcon: Remapping primary device, fb0, to tty 1-63 Dec 21 22:46:10 daphne kernel: calling mux switch 0 Dec 21 22:46:10 daphne kernel: mux switched 0 Dec 21 22:46:10 daphne kernel: ACPI Error: Needed [Buffer/String/Package], found [Integer] ffff880146f23420 (20101013/exresop-590) Dec 21 22:46:10 daphne kernel: ACPI Exception: AE_AML_OPERAND_TYPE, While resolving operands for [OpcodeName unavailable] (20101013/dswexec-460) Dec 21 22:46:10 daphne kernel: ACPI Error: Method parse/execution failed [_SB_.PCI0.GFX0._DSM] (Node ffff880147c6d1c8), AE_AML_OPERAND_TYPE (20101013/psparse-537) Dec 21 22:46:10 daphne kernel: ACPI Error: Method parse/execution failed [_SB_.PCI0.PEG1.GFX0._DSM] (Node ffff880147c83830), AE_AML_OPERAND_TYPE (20101013/psparse-537) Dec 21 22:46:10 daphne kernel: failed to evaluate _DSM: 12291 Dec 21 22:46:10 daphne kernel: vga_switcheroo: switching failed stage 2 12291

-- here need to press power button to force shutdown ---

Second case (echo "OFF"...):

Dec 21 22:43:44 daphne kernel: VGA switcheroo: switched nouveau off Dec 21 22:43:44 daphne kernel: [drm] nouveau 0000:01:00.0: Disabling fbcon acceleration... Dec 21 22:43:44 daphne kernel: [drm] nouveau 0000:01:00.0: Unpinning framebuffer(s)... Dec 21 22:43:44 daphne kernel: [drm] nouveau 0000:01:00.0: Evicting buffers... Dec 21 22:43:44 daphne kernel: [drm] nouveau 0000:01:00.0: Idling channels... Dec 21 22:43:44 daphne kernel: [drm] nouveau 0000:01:00.0: Suspending GPU objects... Dec 21 22:43:45 daphne kernel: [drm] nouveau 0000:01:00.0: And we're gone! Dec 21 22:43:45 daphne kernel: nouveau 0000:01:00.0: PCI INT A disabled Dec 21 22:43:45 daphne kernel: nouveau 0000:01:00.0: power state changed by ACPI to D3

starting X hangs the machine immediately.

Let me know if I can help more.

Hope to hearing from you soon, Giacomo, Italy.

--- ASUS U30JC Gentoo Linux. x11-drivers/xf86-video-nouveau 0.0.16_pre20101130 * drm-nvidia-switch git branch (checkout on dec,22nd)

Giacomo Strangolino Elettra Synchrotron Radiation Facility Trieste, Italy