>> It may not be possible to drive certain types of display with the
>> usual code (as is the case with the PixelStamp, no direct FB access).
>> Rather than teaching the X server about each of the black sheep, why
>> not have a flag passed down by the kernel?
>
> This looks awfully like exposing a bunch of functions to userland and
> let the driver decide which ones to accelerate by hardware... before we
> know it we have half a GDI in the kernel.

I wasn't being clear there, sorry. The reason I suggest the flag is so
that the X server does not try to drive boards that actually require
special code to display anything useful. It should have code to deal
with them, but if it doesn't there's no harm in giving the user a
helpful message instead of displaying garbage.

Andrew