Just out of curiosity... Why did you post two nearly identical versions of this message? On Wed, 29 Aug 2012, Mathew Binkley wrote: > Hi all. How can you associate a USB Bus:Device info with a /dev/entry? There is no general way to do this because most USB devices don't have entries under /dev. However I gather that you're talking about USB mass storage devices in particular; for these it is possible. > Below I have copy/pasted lsusb and /sys/block entries for two drives > plugged into the same USB bus. > > When there was only one USB key, I could simply take the Bus number > (with leading 0's trimmed off) and > > ls -alh /sys/block | grep /usbB/ # B is the bus number > > That heuristic fails when there is more than one drive on the same bus. > The "lsusb" Device number has no discernible match in the > corresponding /sys/block path > > Can anyone give me any advice? There is no direct way. You have to do a search. > --- > > lsusb: > > Bus 003 Device 013: ID 0930:6545 Toshiba Corp. Kingston DataTraveler 102 > Flash Drive / HEMA Flash Drive 2 GB / PNY Attache 4GB Stick > > Bus 003 Device 015: ID 0781:5406 SanDisk Corp. Cruzer Micro U3 > > > /sys/block: > > sdc -> > /sys/devices/pci0000:00/0000:00:16.2/usb3/3-3/3-3:1.0/host16/target16:0:0/16:0:0:0/block/sdc > > sdd -> > /sys/devices/pci0000:00/0000:00:16.2/usb3/3-4/3-4:1.0/host18/target18:0:0/18:0:0:0/block/sdd >From the /sys/block/sdX directory, go up 6 levels and read the contents of the "busnum" and "devnum" files there. You'll have to look through the various sdX entries to find the proper match. Here an example from my system (this is a DVD drive rather than a flash drive, so I'm using srX instead of sdX, but the idea is the same): lsusb: Bus 001 Device 002: ID 059f:0202 LaCie, Ltd StudioDrive USB2 /sys/block/sr0 -> ../devices/pci0000:00/0000:00:1f.1/ata2/host1/target1:0:0/1:0:0:0/block/sr0/ /sys/block/sr1 -> ../devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4:2.0/host2/target2:0:0/2:0:0:0/block/sr1/ $ cat /sys/block/sr0/../../../../../../busnum cat: /sys/block/sr0/../../../../../../busnum: No such file or directory $ cat /sys/block/sr1/../../../../../../busnum 1 $ cat /sys/block/sr1/../../../../../../devnum 2 The busnum and devnum values for sr1 match the Bus and Device values from lsusb, so the LaCie StudioDrive is /dev/sr1. Of course, you could tell just by looking at the full path that the sr0 device wasn't USB. But if it was, the busnum/devnum values would be different from those of the LaCie drive. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
