Messages in this thread | | | Date | Thu, 25 Aug 2016 10:30:45 -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:
> I'd see it as follows: > > #cat available_ports > #1-1 1-2 2-1 > > #echo "1-1" > new_port > > #cat observed_ports > #1-1 > > #echo "2-1" > new_port > > #cat observed_ports > #1-1 2-1 > > We've already had few discussions about the sysfs designs trying > to break the one-value-per-file rule for LED class device, and > there was always strong resistance against.
This scheme has multiple values in both the available_ports and observed_ports files. :-( Not that I have any better suggestions...
> >> Also a description of the device connected to the port would be a nice > >> feature, however I am not certain about the feasibility thereof. > > > > 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.
Alan Stern
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