Re: POSTing of video cards (WAS: Solo Xgl..)

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, 22 Feb 2005 11:19:10 -0800 (PST), Linus Torvalds
<torvalds@osdl.org> wrote:
> 
> 
> On Mon, 21 Feb 2005, Jon Smirl wrote:
> >
> > I was working on the assumption that all PCI based, VGA class hardware
> > that is not the boot device needs to be posted.
> 
> I don't think that's true. We certainly don't _want_ it to be true in the
> long run - and even now there are cards that we can initialize fully
> without using the BIOS at all.
> 
> > And that the posting should occur before the drivers are
> > loaded.
> 
> Personally, I'd much rather let the driver be involved in the decision.
> 
> That may mean that the probe routine knows how to initialize the card, but
> it may mean that it does an "exec_usermodehelper()" kind of thing.
> Actually, I'd prefer it if this was largely up to "udev": if the driver
> notices that it can't initialize the card, why not just enumerate it
> enough that "udev" knows about it (that's pretty much automatic), and let
> the driver just ignore the card until some (possibly much later) date when
> the user level scripts have found it and initialized it.
> 
> That would imply that the driver have some "re-attach" entrypoint (which
> migth be a ioctl, but might also be just a /sysfs file access), which is
> the user-lands way of saying "try again - I've now initialized the
> hardware".
> 

This sounds awfully like firmware loader that seems to be working just
fine for a ranfe of network cards and other devices.

-- 
Dmitry