Re: [patch 1/2] fastboot: Add a module parameter to skip probing ofspecific ports

From: Arjan van de Ven
Date: Tue Aug 12 2008 - 10:02:25 EST


On Tue, 12 Aug 2008 13:00:27 +0100
Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:

> > > What
> > > defines the probe order here particularly as people are pushing
> > > for parallel probing of multiple devices.
> >
> > the patches I'm pushing for this don't change probe order; that has
> > been tried before and wasn't a great success.
>
> That was a question sorry. You are sledgehammering controllers by
> discovery sequence - you've no idea if they will always be found in
> that order. As such your boot option is incredibly fragile.

ok to answer your question;
today the probe order is consistent, at least on netbooks.
The admin or his installation program knows it when he has this (and if
linux were to grow full parallel probing it'll be optional, and if the
admin wants a fast boot he'll disable the parallel, reordering probe)
and can add the option for this case. It's the "push policy out of the
kernel" thing.. while the kernel probably can't know this (and you're
right, the DMI patch is thus the wrong thing to do).. the admin can.



--
If you want to reach me at my work email, use arjan@xxxxxxxxxxxxxxx
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/