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SubjectRe: [Dri-devel] Re: [Linux-fbdev-devel] DRM and pci_driver conversion
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Linus Torvalds <torvalds@osdl.org> writes:

> On Sat, 25 Oct 2003, Egbert Eich wrote:
> >
> > Speaking of XFree86: when I developed the PCI resource stuff in
> > XFree86 I was trying to get support from kernel folks to get the
> > appropriate user space interfaces into the kernel. When I got
> > nowhere I decided to do everything myself.
>
> There won't be any "user space interfaces". There are perfectly good
> in-kernel interfaces, and anybody who needs them needs to be in kernel
> space. Ie the kernel interfaces are for kernel modules, not for user space
> accesses.

Well almost. There is still one significant flaw in the kernel space stuff.

The BIOS can specify arbitrary regions as reserved in the E820 map and then
a kernel driver can't use that region itself. This shows up in corner
cases where the resource on the PCI device is a boolean rather than
a general purpose thing. Particularly for mtd map drivers to allow
flashing your ROM from linux this is a problem.

This is not required for 2.6.0 but it would be nice to actually be able
to reliably reserve resources in kernel drivers.

Eric
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