[Bug 34252] New: Unexpected behaviour when switching video cards with vga_switcheroo

[bugzilla-daemon@bugzilla.kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=34252

           Summary: Unexpected behaviour when switching video cards with
                    vga_switcheroo
           Product: Drivers
           Version: 2.5
    Kernel Version: 2.6.39-rc5+ (1be6a1f89f131e9c3d22f819ec542be9cda8c9e3)
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Video(DRI - non Intel)
        AssignedTo: drivers_video-dri@kernel-bugs.osdl.org
        ReportedBy: e-mail@date.by
                CC: alexdeucher@gmail.com
        Regression: Yes


Created an attachment (id=56262)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=56262)
Kernel config

Trying to setup script, that switches video cards, I ran into the situation
when I left with a black screen not possible to do anything with the system.
Here is an example:

# cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD:+:Pwr:0000:01:05.0
1:DIS: :Pwr:0000:02:00.0
# echo IGD > /sys/kernel/debug/vgaswitcheroo/switch
# cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD:+:Off:0000:01:05.0
1:DIS: :Pwr:0000:02:00.0

I think that this behaviour is buggy and this should not happen.

Environment:
# lspci | grep -i vga
01:05.0 VGA compatible controller: ATI Technologies Inc RS780M/RS780MN [Radeon
HD 3200 Graphics]
02:00.0 VGA compatible controller: ATI Technologies Inc M93 [Mobility Radeon HD
4500 Series]
# uname -a
Linux garik-laptop 2.6.39-rc5+ #8 SMP Sat Apr 30 18:36:12 MSD 2011 x86_64 AMD
Athlon(tm) Neo Processor MV-40 AuthenticAMD GNU/Linux

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