On Tue, Jan 15, 2013 at 11:07 PM, David Milburn <dmilburn@xxxxxxxxxx> wrote: > As low-level drivers register their host controller(s), keep track > of the number of controllers and export thru /sys in a <host.port> > format so that udev can better match up port numbers with a > specific controller. Hmm, I tried this and I don't think it will solve out problem. But I might have missed something ... This is host 2 with port "7", but it is really port 1: > ./0000:00:1e.0/0000:05:01.0/ata2.7 > ./0000:00:1e.0/0000:05:01.0/ata2.7/link7/dev7.0/ata_device This is host 1 with port "6": > ./0000:00:1f.2/ata1.6/ata_port > ./0000:00:1f.2/ata1.6/ata_port/ata1.6 The host number is meaningless regarding stable identifiers, as it depends on probing/driver binding order. Now, the port number is still *global* across all all controllers, and therefore also not useful. We need *host-local* numbers, which share nothing with other hosts, so the drivers and bus enumeration order can change at any time without affecting any of the device numbers used inside the host. I have not much clue about port-multipliers, never seen them, but if we want to support arbitrary stacking of them we will need to compose a "chain of numbers" in the "stable identifier" out of the individual port numbers they are connected to, very much like USB hub chaining works. This means we will need every instance in the chain to start with their own numbers again. Any global counters used for device naming/enumeration are not useful to identify devices from userspace. Thanks, Kay -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
