On Fri, Mar 29, 2019 at 09:48:23AM +0100, Marek Behun wrote: > > pavel@amd:~/cip$ cat /sys/power/state > > freeze mem disk > > pavel@amd:~/cip$ cat /sys/class/leds/phy0-led/trigger > > none bluetooth-power rfkill-any rfkill-none kbd-scrolllock kbd-numlock > > kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock > > kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock > > AC-online BAT0-charging-or-full BAT0-charging BAT0-full > > BAT0-charging-blink-full-solid rfkill0 phy0rx phy0tx phy0assoc > > phy0radio [phy0tpt] mmc0 timer heartbeat audio-mute audio-micmute > > rfkill1 hci0-power rfkill8 > > pavel@amd:~/cip$ > > > > Yes, and cpufreq governors too list available governosrs as space > separated list. > Maybe the "one value per file" rule was thought-of only after these > were merged?
For small numbers of things, like /sys/power/state, which was the first file to use this style, it was fine as we "knew" this was going to be a small, well-bounded list of states that the file could be in. As you have seen, 'trigger' is not that, and I am pretty sure I have complained about this in the past. I suggest you use a different way of "discovering" what types of triggers are available. I don't know what would work best for you, but any time you are ever worried about the size of a sysfs file's buffer, you know you are doing something wrong. thanks, greg k-h
