Re: MTRR problem, maybe FB related

[Sebastian <admin@wodkahexe.de>]

On Fri, 6 Aug 2004 21:34:36 +0100
Dave Jones <davej@redhat.com> wrote:

> On Fri, Aug 06, 2004 at 07:47:22PM +0200, admin@wodkahexe.de wrote:
> 
>  > vesafb: framebuffer at 0xb0000000, mapped to 0xdf80d000, size 6144k
>  > vesafb: mode is 1024x768x32, linelength=4096, pages=4
> 
> vesafb's mtrr usage is borken. Instead of creating an MTRR the size
> of video RAM, it creates one the size of the display.
> 
>  > mtrr: 0xb0000000,0x8000000 overlaps existing 0xb0000000,0x400000
>  > [drm] Initialized i830 1.3.2 20021108 on minor 0: Intel Corp. 82852/855GM Integrated Graphics Device
>  > mtrr: 0xb0000000,0x8000000 overlaps existing 0xb0000000,0x400000
>  > [drm] Initialized i830 1.3.2 20021108 on minor 1: Intel Corp. 82852/855GM Integrated Graphics Device (#2)
> 
> Then X comes along, sizes the video ram, and tries to create an MTRR
> of the correct size, but the framebuffer got there first and bodged it.
> 
> I used to see this happening also on my Matrox g550, but it seems
> to have 'gone away' in recent times. I haven't checked out why,
> but I'm suspecting X now detects this case, and deletes the crap
> entry, and puts the proper values in its place.
> 
>  > when starting X i'm getting the following in dmesg:
>  > 
>  > mtrr: base(0xb0020000) is not aligned on a size(0x180000) boundary
> 
> This one I can't explain however.
> 
>  > mtrr: 0xb0000000,0x8000000 overlaps existing 0xb0000000,0x400000
>  > 
>  > is there any way to get both working together? (fb + mtrr)
> 
> Disable MTRR for vesafb. iirc, there's a boot command line option to do it.
> 
> 		Dave
> 

Ah, I see. It's not documented in Documentation/fb/vesafb.txt, but after
looking at drivers/video/vesafb.c i got it (video=vesafb:nomtrr).
Now it seems to work, but X still gives me upon starting:

mtrr: base(0xb0020000) is not aligned on a size(0x180000) boundary

thanks

sebastian