Messages in this thread | | | Date | Thu, 25 Aug 2016 15:35:49 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger |
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On Thu, 25 Aug 2016, Jacek Anaszewski wrote:
> >>> What kind of description do you mean? Where should it be used / where > >>> should it appear? > >>> > >> > >> Product name/symbol. Actually it should be USB subsystem responsibility > >> to provide the means for querying the product name by port id, if it > >> is possible at all. > > > > cat /sys/bus/usb/devices/PORT/product > > cat /sys/bus/usb/devices/PORT/manufacturer > > > > These will work if there is a device registered under PORT. > > I've found only idProduct and idVendor files. They indeed uniquely > identify the device, but the numbers are not human readable. > Is there a way to retrieve the corresponding names in kernel?
If the device provides the string descriptors then the textual product and manufacturer files are available in sysfs, otherwise they aren't.
> Does the lsusb command do the mapping in the user space or maybe > it takes the names from kernel?
lsusb does the mapping in userspace, based on an ID database. On my system (Fedora), the database is /etc/udev/hwdb.bin.
Alan Stern
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