Re: [gentoo-user] uvesafb fails to work

[Daniel Pielmeier]

Mick schrieb:
> On Sunday 30 March 2008, Daniel Pielmeier wrote:
>> Mick schrieb:
>>> Hi All,
>>>
>>> I've just compiled kernel-2.6.24-gentoo-r3 which comes with uvesa and
>>> thought of using it on a box of mine.  However, amidst other weird and
>>> wonderful errors that the new kernel gives me on this box, I have
>>> completely failed to get uvesafb to work.
>>>
>>> When it boots up it comes up with these errors:
>>> =====================================================
>>> * Setting framebuffer console images
>>> Can't open cfg file //etc/splash/emergence/640x480.cfg
>>> No 8bpp silent picture specified in the theme
>>> No 8bpp verbose picture specified in the theme
>>> * Failed to set background image on tty1
>>> =====================================================
>>>
>>> Meanwhile the penguins and fonts on the boot console are shown in some
>>> impossibly large size.  My kernel line is:
>>>
>>> kernel /kernel-2.6.24-gentoo-r3 root=/dev/sda3 \
>>> video=uvesafb:1280x1024-32@60,ywrap,mtrr:4, \
>>> splash=silent,fadein,theme:emergence quiet CONSOLE=/dev/tty1
>>> initrd /boot/fbsplash-emergence-1280x1024
>>>
>>> Any ideas?
>> Just a shot in the dark are you using any kind of tv-out?
>>
>> I had this problem with tv-out. I specified a resolution of 1280x1024.
>> When I connect my tv to my box the maximal resolution possible is
>> 1024x768 because the tv-encoder does not offer higher resolutions. So
>> instead of switching to the next greatest resolution of 1024x768 the
>> uvesafb driver switches to smallest resolution of 640x480. This
>> resolution is not available in the emergence theme thus the splash fails!
>>
>> If you have a problem like this there are existing patches whto the
>> kernel which are fixing this issue!
>>
>> What does "cat /sys/devices/platform/uvesafb.0/vbe_modes" say?
>
> Thanks Daniel, I am not using tvout, just a LCD monitor.  You're right,
> there's no 1280x1024 in the above file!  Changed it to 1024x768 and it works,
> although the quality of the image is poor (it looks sort of pixelated).
>
> What controls what resolutions exist in that file?

Output of /usr/src/linux/Documentation/fb/uvesafb.txt

... snip ....

2. Caveats and limitations
--------------------------

uvesafb is a _generic_ driver which supports a wide variety of video
cards, but which is ultimately limited by the Video BIOS interface.
The most important limitations are:

- Lack of any type of acceleration.
- A strict and limited set of supported video modes.  Often the native
   or most optimal resolution/refresh rate for your setup will not work
   with uvesafb, simply because the Video BIOS doesn't support the
   video mode you want to use.  This can be especially painful with
   widescreen panels, where native video modes don't have the 4:3 aspect
   ratio, which is what most BIOS-es are limited to.
- Adjusting the refresh rate is only possible with a VBE 3.0 compliant
   Video BIOS.  Note that many nVidia Video BIOS-es claim to be VBE 3.0
   compliant, while they simply ignore any refresh rate settings.

..... snip .....

4. The sysfs interface
----------------------

uvesafb provides several sysfs nodes for configurable parameters and
additional information.

Driver attributes:

/sys/bus/platform/drivers/uvesafb
   - v86d (default: /sbin/v86d)
     Path to the v86d executable. v86d is started by uvesafb
     if an instance of the daemon isn't already running.

Device attributes:

/sys/bus/platform/drivers/uvesafb/uvesafb.0
   - nocrtc
     Use the default refresh rate (60 Hz) if set to 1.

   - oem_product_name
   - oem_product_rev
   - oem_string
   - oem_vendor
     Information about the card and its maker.

   - vbe_modes
     A list of video modes supported by the Video BIOS along with their
     VBE mode numbers in hex.

   - vbe_version
     A BCD value indicating the implemented VBE standard.

..... snip .....


So this depend on the Video Bios of your card and you maybe can't do 
anything about it!

Although 1280x1024 should normally work and i guess you use this 
resolution for your Desktop. How do you generate your initrd? Which card 
do you have?

"dmesg | grep uvesafb" and "fbset --info -v"?

Regards,

Daniel

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