Re: MTRR setting and framebuffer driver

Jeff Garzik (jgarzik@pobox.com)
Tue, 14 Sep 1999 21:29:34 -0400

Jamie Lokier wrote:
> So vesafb would have to scan the resource tree looking for a parent
> region. And then how can it be sure the remaining 1.5MB of resource
> isn't allocated? Hook the tree so the MTRR is removed if the parent
> region is allocated, or allocate the extra portion (may not be safe).
>
> But the real point is: should vesafb be making assumptions about MTRR
> alignment requirements? That may change with another CPU, so I think it
> is the responsibility of the MTRR driver.

That knowledge is the responsibility of the MTRR driver, but not
necessarily the actions. If the mem region is not aligned properly, the
driver is in the best position to decide whether it should relocate its
device region, or if that is even possible.

What about a resource flag IORESOURCE_MTRR which indicates a region can
be used with MTRRs?

Regards,

Jeff

-- 
Custom driver development	|    Never worry about theory as long
Open source programming		|    as the machinery does what it's
				|    supposed to do.  -- R. A. Heinlein


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/