Re: Next round of console patches

Richard Gooch (rgooch@atnf.csiro.au)
Sun, 30 Aug 1998 08:28:26 +1000


Gerd Knorr writes:
> [ lockup with vesafb + mtrr + Millennium 2MB ]
>
> > vesafb: framebuffer at 0xa0800000, mapped to 0xc8800000, size 2048k
>
> Ok, size is correct. Base address probably too, otherwise you
> would'nt see anything...
>
> Richard, any idea what is wrong there? vesafb will try to create a
> mtrr entry for the framebuffer: base=0xa0800000, 2 MB size. This
> locks the machine (which can be "fixed" by disabling mtrr in .config).

Sorry, I haven't been following this thread. At what point does the
machine lock up? Is it as soon as the MTRR region is setup, or later
(such as when you do graphics operations or change video modes)?

Perhaps the first/last few kBytes of the framebuffer have control
registers rather than display memory? In that case, write-combining
could foul up the card. You can fix this by making a uncacheable
region for the registers.

Regards,

Richard....

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