[Nouveau] Activate DVI-I behind KVM on FX 5200

[poma]

On 05.01.2016 04:08, Thomas Richter wrote:
> Hi folks,
> 
> I don't seem to be able to enable the DVI-I output of an old FX 5200
> behind a KVM switch. Autodetection works fine if the FX 5200 DVI output
> is switched to the monitor, but when it is not, I have not found a way
> to force-enable it.
> 
> Here is what I tried:
> 
> *) used the video=DVI-I-1:1280x1024-24 at 60e kernel parameter
> (framebuffer still sits at 1024x768)
> 
...

Tested here,

in "video=DVI-I-1:1280x1024-24 at 60e" directive
problematic are:

color depth (bpp) 24
-and-
'e' as "forced display enablement"

causing display -switching off- at the exact moment:
fb: switching to nouveaufb from VESA VGA


Contrairement à ce que,
these 3 examples have been successfully tested:

1.  video=DVI-I-1:1280x1024
2.  video=DVI-I-1:1280x1024 at 60
3.  video=DVI-I-1:1280x1024-16 at 60

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

# cat /proc/cmdline
... video=DVI-I-1:1280x1024 ...


# fbset -i

mode "1280x1024"
    geometry 1280 1024 1280 1024 32
    timings 0 0 0 0 0 0 0
    accel true
    rgba 8/16,8/8,8/0,0/0
endmode

Frame buffer device information:
    Name        : nouveaufb
    Address     : 0xd0006000
    Size        : 5242880
    Type        : PACKED PIXELS
    Visual      : TRUECOLOR
    XPanStep    : 1
    YPanStep    : 1
    YWrapStep   : 0
    LineLength  : 5120
    Accelerator : No


# dmesg -t | egrep fb:\ 0x
nouveau 0000:02:00.0: DRM: allocated 1280x1024 fb: 0x50000, bo ffff88007f5d2800

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

# cat /proc/cmdline
... video=DVI-I-1:1280x1024 at 60 ...


# fbset -i

mode "1280x1024"
    geometry 1280 1024 1280 1024 32
    timings 0 0 0 0 0 0 0
    accel true
    rgba 8/16,8/8,8/0,0/0
endmode

Frame buffer device information:
    Name        : nouveaufb
    Address     : 0xd0006000
    Size        : 5242880
    Type        : PACKED PIXELS
    Visual      : TRUECOLOR
    XPanStep    : 1
    YPanStep    : 1
    YWrapStep   : 0
    LineLength  : 5120
    Accelerator : No

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

# cat /proc/cmdline
... video=DVI-I-1:1280x1024-16 at 60 ...


# fbset -i

mode "1280x1024"
    geometry 1280 1024 1280 1024 16
    timings 0 0 0 0 0 0 0
    accel true
    rgba 5/11,6/5,5/0,0/0
endmode

Frame buffer device information:
    Name        : nouveaufb
    Address     : 0xd0006000
    Size        : 2621440
    Type        : PACKED PIXELS
    Visual      : TRUECOLOR
    XPanStep    : 1
    YPanStep    : 1
    YWrapStep   : 0
    LineLength  : 2560
    Accelerator : No



Ref.
https://www.kernel.org/doc/Documentation/fb/modedb.txt

p.s.
Can you paste here the output of these two oneliners:
$ cd /sys/class/drm ; ls -1d card0-* | sed s/card0-// | sort
$ xrandr | grep connected | awk '{print $1}' | sort