[Bug 55311] Since 3.7.1-17.1 radeon has no backlight when using vgaswitcheroo (regression)

[bugzilla-daemon at bugzilla.kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=55311

arkaitzj at gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |arkaitzj at gmail.com

--- Comment #68 from arkaitzj at gmail.com ---
Is it possible that this same bug happens between nouveau and i915?
I have a macbookpro9,1 running a discrete nvidia and an igd intel, I boot a
Debian and starts always with the DIS card, however, switching to the intel one
only gives me a black screen.
This gives me 15 seconds of a black screen

echo IGD > switch && sleep 15 && echo DIS > switch

This is how the system starts:
# cat /sys/kernel/debug/vgaswitcheroo/switch 
0:IGD: :Pwr:0000:00:02.0
1:DIS:+:Pwr:0000:01:00.0
2:DIS-Audio: :Pwr:0000:01:00.1

I have compiled several kernels from 3.6.10 to current linux-stable:v3.12-rc2
but they all show the same symptoms.

Drivers are nouveau and i915 and there are no oops or weird kernel messages,
all looks normal in dmesg

-- 
You are receiving this mail because:
You are on the CC list for the bug.