On 7 Jan 2003, Alan Cox wrote:
>
> On Tue, 2003-01-07 at 00:13, Grant Grundler wrote:
> > On Mon, Jan 06, 2003 at 03:19:09PM -0800, Linus Torvalds wrote:
> > > In particular, we can make the first phase disable DMA on the devices we
> > > find, which means that we know they won't be generating PCI traffic during
> > > the second phase - so now the second phase (which does the BAR sizing) can
> > > do sizing and be safe in the knowledge that there should be no random PCI
> > > activity ongoing at the same time.
> >
> > Did you expect the PCI_COMMAND_MASTER disabled in the USB Controller
> > or something else in the controller turned off?
>
> There is another problem too. Some devices ignore the master bit disable.
> VIA 8233/8235 being a fine example.
Well, I was actually thinking of really _stopping_ the USB controller and
disable DMA that way. That's easy to do with a few trivial fixups - one
for each USB controller type (and there are only three).
Because of legacy USB handling by the SMM BIOS, USB really ends up being a
special case. There may be other special cases, of course, but the whole
point of the fixups is exactly to handle special cases.
Linus
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Tue Jan 07 2003 - 22:00:36 EST