On Tue, Mar 04, 2008 at 03:58:30PM -0700, Alex Chiang wrote: > * Greg KH <gregkh@xxxxxxx>: > > 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 > > No guarantee there. We report whatever firmware tells us. > > > > > and do not happen to be the same as the hotpluggable ones? > > Stronger guarantee here, since both pci_slot and <foo>hp driver > will be getting the name of the slot from the same place. > > > > 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? > > We saw problems on Fujitsu machines, where they return an error > code when the _SUN method is called on a slot that exists in the > namespace but isn't actually present. > > After discussing with Kenji-san about specs, we came to the > agreement that he was ok with this behavior because he had the > option to not load pci_slot on his machines. > > I agree that there might be lots of buggy firmwares out there, > but we won't know for certain until we get some exposure. And I > think the upside is worth it. > > Kristen suggested the linux-next tree. That sounds viable to > me... > > > > > Why show this information on machines that can not do > > > > anything with these slots at all? Will that not just > > > > confuse people? > > > > > > Only for people who think that /sys/bus/pci/slots/ is for > > > hotpluggable slots only. There is plenty of useful > > > information available for slots that aren't hotpluggable (eg > > > bus address, speed, width, error status). > > > > Can the userspace tools that are using the existing directories > > thinking that only hotplug slots are there, handle > > "non-hotplug" slots showing up in this location? > > Of course we shouldn't break userspace, no one wants that. But > nothing about that name (/sys/bus/pci/slots/) implies "hotplug > only", and we have no idea how big the problem might be. But that is what the current code does, so I know a lot of userspace programs assume that all slots there are valid hotplug slots. I know I sure don't want to go fix up a lot of horrible Java closed-source code in IBM's huge system management toolkits :( > Again, I'm thinking more exposure in linux-next might be a > reasonable way for us to figure out how bad (or good) the > situation might really be out there. Ok, care to resend them with the requested updates? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
