On Mon, Sep 08, 2008 at 09:12:29PM -0700, Jesse Barnes wrote: > I don't have a preference here; whatever is most useful for people is probably > what we should go for. Zhao? I think we have two distinct groups of users; those who find emulating slot hotplug useful, and those who want to hot-remove pci functions. Maybe hot-removing a pci function should not be part of the pci hotplug core per se -- obviously it would share much code -- but being able to hot-remove a function is a fundamentally different thing from being able to hot-remove a slot. For example, hot-removing a function from a device that is in a real hotplug slot should be possible, but it wouldn't involve the driver for that hotplug slot. So maybe what we want is a /sys/bus/pci/devices/dddd:bb:dd.f/remove file that does just that. Oh, and we also want a way to hot-add functions, not necessarily even ones that have been removed from the machine after it was booted, but those that show up after the machine has booted. For example, one of my former colleagues had a laptop which would remove the wireless pci device from the bus if the rfkill switch was enabled. I remember there was a hack to load a module that called some pci bus rescan functionality. I didn't look into it in much detail. I don't have a firm idea about an interface for this. SCSI handles it by writing scsi-add-single-device H C T L to /proc/scsi/scsi. Maybe we want a /sys/bus/pci/scan or /sys/bus/pci/devices/scan file that we can echo "0000:01:02.3" to scan just that function, or "0000:01:02" to scan the device. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
