On 12/17/19 6:21 PM, Greg Kroah-Hartman wrote: > On Tue, Dec 17, 2019 at 05:23:13PM +0100, Uwe Kleine-König wrote: >> On Tue, Dec 17, 2019 at 04:27:24PM +0100, Greg Kroah-Hartman wrote: >>> On Tue, Dec 17, 2019 at 04:07:36PM +0100, Uwe Kleine-König wrote: >>>> Usage is as follows: >>>> >>>> myled=ledname >>>> tty=ttyS0 >>>> >>>> echo tty > /sys/class/leds/$myled/trigger >>>> cat /sys/class/tty/$tty/dev > /sys/class/leds/$myled/dev >>> >>> Is this the correct instructions? Aren't you looking for a major/minor >>> number instead in your sysfs file? >> >> This is correct, yes, at least it works as intended on my machine. >> >> /sys/class/tty/$tty/dev produces $major:$minor and that's what the >> led-trigger consumes. > > Ugh, nevermind, I totally read that wrong, I was thinking "echo" instead > of cat. My fault, what you wrote is correct. Should that be documented > somewhere in a Documentation/ABI/ file so that people know how to use > this new sysfs file? How are led triggers documented? LED triggers have their corresponding entries in Documentation/ABI. Uwe, you already did that for netdev trigger: Documentation/ABI/testing/sysfs-class-led-trigger-netdev It would be nice to have one for this too. There are also less formal docs in Documentation/leds, e.g.: Documentation/leds/ledtrig-usbport.rst -- Best regards, Jacek Anaszewski
