Re: [PATCH 4/4] ACPI PCI slot detection driver

On Tue, 4 Mar 2008 11:30:36 -0800
Greg KH <gregkh@xxxxxxx> wrote:

On Tue, Mar 04, 2008 at 10:18:28AM -0800, Jesse Barnes wrote:
On Monday, March 03, 2008 9:49 pm Greg KH wrote:
On Sat, Mar 01, 2008 at 07:43:07AM -0700, Matthew Wilcox wrote:
On Fri, Feb 29, 2008 at 09:25:42PM -0800, Greg KH wrote:
What is the guarantee that the names of these slots are
correct and do not happen to be the same as the hotpluggable
ones?

That would be a bug -- and yes, bugs happen, and we have to
deal with them.

My main concern is that BIOS vendors will not fix these bugs, as
no other OS cares/does this kind of thing today. The ammount of
bad information out there might be quite large, and I think this
was confirmed by some initial testing of IBM systems, right?

Yeah, but there's a flip side to this too: if no one uses the
data, no one will complain when it's wrong. If Linux starts making
it easy to see this stuff, there's a chance system vendors will
start taking an extra 5 min. before shipment to make sure that the
BIOS info is up to date...

OTOH, I'm not sure which is worse, bad data or no data.

bad data is worse.

And then there's the machines with duplicate slot names, how does this
code handle PCI slots with that? I think some of the IBM machines had
non-hotplug slots named the same as the hotplug slots, right?

This stuff needs a _lot_ of testing on a lot of different machines,
and a sane way to fall-back if there are errors to ensure that working
machines don't break.

And then there's the issue with userspace programs only expecting
hotplugable slots in the slots/ directory...

thanks,

greg k-h


I too worry about interaction with other vendor's machines, so maybe we
should make it easier to test by putting this series into linux-next?

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