Problem with xorg-server and s3c2410fb driver

[Michel Dänzer]

On Son, 2010-07-25 at 09:35 +0300, Vasily Khoruzhick wrote: 
> Hi,
> 
> I'm trying to get xorg-server + xf86-video-fbdev working on my device, and I'm 
> hitting problem:
> 
> pixclock value of fb mode on my device is 260000 picosecs, and due to picosecs 
> <-> khz conversions in xorg-server I'm getting rounding error:
> 
> 1000000000 / 260000 = 3846
> 1000000000 / 3846 = 260010
> 
> (Look through xfree2fbdev_timing and fbdev2xfree_timing functions in fbdevhw.c
> for more details)
> 
> xorg-server gets mode via FBOIGET_VSCREENINFO (pixclock = 260000), converts it 
> to its own format, then converts it back to fbmode (due to rounding error 
> pixclock - 260010) and then tries to set mode with pixvalue 260010 via 
> FBIOPUT_VSCREENINFO ioctl, but driver sets it back to 260000, and xorg-server 
> fails to startup with this message:
> 
> (EE) FBDEV(0): FBIOPUT_VSCREENINFO succeeded but modified mode.

What version of xserver are you using? It sounds like your problem
should be fixed by Git commit bf333c2f9833a178887e7bdd7fc338f1e09c387f
('fbdevhw: Remove pixclock check.') which should be included since 1.6.x
at least.


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer