On Mon 2016-08-29 10:21:48, Rafał Miłecki wrote: > On 29 August 2016 at 10:05, Pavel Machek <pavel@xxxxxx> wrote: > >> >2) Having "ports" subdir with RW files, one per each existing physical port > >> >In this situation we don't need "new_port" or "remove_port". If we > >> >want port to be observable we just do: > >> >echo 1 > 1-1 > >> >Implementing this solution needs reading more details from USB subsystem. > >> > >> The situation here is clear IMO - the number of USB ports in the system > >> can change dynamically. I'm not sure if this can be handled easily with > >> sysfs, where we usually expose an interface for known set of settings. > >> struct attribute arrays are usually defined statically at the compile > >> time and filled with the variables, that are created with DEVICE_ATTR > >> macro. > > > > sysfs already exposes current view of all usb devices. Just use it. > > We're talking about USB ports not devices, but this is still true. You > can find them in > /sys/bus/usb/devices/*/*-port* > > I can't see how we could use them. How could I develop sysfs interface > in /sys/class/leds/*/ to allow userspace assigning USB ports to the > LED trigger? Create /sys/bus/usb/devices/*/*-port*/led_trigger file? (Do you plan one USB trigger, or multiple ones?) Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
