Re: G550 bug ? (was Re: Independ multiple users on G550)

[Petr V. <VAN...@vc...>]

On  1 Dec 03 at 17:57, Svetoslav Slavtchev wrote:
> > it is impossible for yres_virtual to ever become 65536... Besides that
> > for 1024x65536/16bpp you need 128MB of videoram, and G550 can have only
> > 32MB. So you screwed something a lot. You should get
> > 
> > matroxfb: Matrox G550 detected
> > matroxfb: MTRR's turned on
> > matroxfb: 1024x768x16bpp (virtual: 1024x8190)
> > matroxfb: framebuffer at 0xDA000000, mapped to 0xe0810000, size 33554432
> > Console: switching to colour frame buffer device 128x48
> > fb0: MATROX frame buffer device
> 
> two questions 
> 1.)
>  is there a way to specify yres_virtual,
>  i can not see such module option

You cannot specify it - you can only say 'yes, I want virtual scrolling'
or 'no, I do not want it'. If you use 'video=matroxfb:nopan', driver will
use yres_virtual == yres. If you do not specify it, driver attempts
to use largest possible value smaller than 65536. Apparently for some
reason fb_set_var() with yres_virtual == 65536 succeeds without
changing passed var, although it should report back truncated yres_virtual....
oh, stop! There is no fb_set_var call in stock matroxfb. Can you try opening
drivers/video/matrox/matroxfb_base.c in your favorite text editor and
locakte

  matroxfb_init_fix(PMINFO2);
  err = -EINVAL;

and add

  fb_set_var(&ACCESS_FBINFO(fbcon), &vesafb_defined);
  
between these two lines there... It should then use proper (~8190) vyres 
instead of 64K. But probably vgacon -> matroxfb will stop working after 
that, and you'll see whole screen as bright white instead of text 
inherited from vgacon.

> 2.) 
>  how should one adjust the mode for head2,
>  matroxfb_crtc2 has only a "mem" option

fbset. crtc2 always begins in 640x480/32bpp, as it cannot be your 
boot monitor, so you can always run fbset. Unless you have 2.6.x fbset-less
kernel, in which case you have just bad luck...

> > I'd say that if you want support from me, you should use my code...
> > I have no idea what you are doing in your tree, but you are apparently
> > doing wrong things...
> 
> just asking :(
> i'm not a kernel programmer, and i'm not familiar with the fb /console
> internals
> if i was i would try to merge your driver, but i'm not so ...
> 
> and as said your driver makes deep changes to the FB API, which IMHO are
> incompatible
> with ruby

Version in kernel just uses standard fbdev API present in 2.6.x kernel.

> i know i can not ask for support at least until 2.7 is open and ruby merged
> into it,
> and even then may be you'll keep your driver out of tree which will
> complicate support questions

Yes, I support only standard Linus (or soon Andrew's) kernel.
                                                                Petr