lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 22 Feb 2017 13:39:29 +0100 From: Pali Rohár <pali.rohar@...il.com> To: Pavel Machek <pavel@....cz> Cc: Richard Purdie <rpurdie@...ys.net>, Jacek Anaszewski <jacek.anaszewski@...il.com>, linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org, Darren Hart <dvhart@...radead.org>, platform-driver-x86@...r.kernel.org Subject: Re: LED devices & poll() for brightness attribute On Wednesday 22 February 2017 13:25:57 Pavel Machek wrote: > Hi! > > > But this support is useful just for one single central userspace > > application which will control all leds in system other application > > which will change state by /sys/class/leds/ will de-synchronize that one > > central application. > > Yes. Does it matter for some real use case? Yes. E.g. systemd has already some support for changing leds. And I do not want to be forced to use systemd (or any other specific application) just because it already controls leds. And my own application for controlling leds should know current state of them if it is possible. > > So I think new ABI is not sufficient and I would propose to add poll() > > support also for changes done by userspace, write() to attribute > > /sys/class/leds/.../brightness. > > Not easily possible, as we have triggers, and this was discussed in > great great lengths before. Please go through that discussion. Without triggers and blinking it should be possible. Just notify only when some application do echo > brightness. -- Pali Rohár pali.rohar@...il.com
Powered by blists - more mailing lists