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gnome-power-manager and blanking (removal of bodges)

I’ve been working with the xorg people upstream, trying to sort out all the remaining blanking problems properly, rather than just working around the problem. I’ll explain the key issues:

gnome-power-manager uses a counter inside Xorg called IDLETIME. This counter is incremented only when the user does not move the mouse, or click some keys. When the user clicks something, the IDLECOUNTER is reset. Unfortunately, the IDLETIME counter was also being reset (in two places!) when the DPMS level is set. Now, this doesn’t affect most users of IDLETIME, as the screen doesn’t blank that often. For the most part, IDLETIME was a welcome addition to the X server.

For gnome-power-manager, we set up a XSync alarm for IDLE counter being over a certain value, and then we set up a XSync alarm for the IDLE counter being reset. When the alarm goes off we wait the policy time for the “display sleep” and then turn off the panel using DPMS. Which then resets the idletime, which turns the panel back on. Urgh.

So, what we do is handle the reset event, and if the event is less than a few milliseconds since we did a DPMS action, we ignore the alarm. Of course, if we ignore the alarm, then we don’t get the reset event when the user moves the mouse and the IDLECOUNTER gets reset. So, in this case, gnome-power-manager sets up a 1ms timeout when we detect an alarm a small time since a DPMS event. This triggers almost immediately, and so we get the alarm fired practically straight away.

Except, due to another X bug, if we set an alarm value on the timer that’s already been passed, we don’t get the alarm fired. So, if you’ve got a high load value, or a slow system, you could miss the alarm. So, we had to raise the bodge alarm value to 50ms, rather than 1ms. Urgh.

But then, there’s a nice 50ms race between the two timers, and 50ms is a small amount of time in human terms, right? No. When the user is reading something, and the display blanks, most users move the mouse pretty much straight away. If you hit this 50ms race (which some people seem able to do, me included) then gnome-power-manager misses the reset event, and if configured to do so, gnome-power-manager will still think your idle, and then go on to suspend your system. Urgh.

So, the only way to fix gnome-power-manager and remove all these ugly kludges would be to fix the xserver. I’ve sent two patches to xorg-devel which remove the IDLECOUNTER reset when DPMS off is sent. The second upstream patch is here.

So, I’ll remove the kludges from gnome-power-manager git master today and will depend on a runtime version of the xserver that has these patches applied. If you are trying to run gnome-power-manager with a broken version of X, gnome-power-manager will warn you in the notification area. Distributors will just need to patch xserver with my previous patch and the current one to have all the issues resolved with git master.

edit: updated with links to the signed off patches in xserver!

cnkilior 写了：所谓的显示服务器的意思是Xserver。。不是显示器，表大惊小怪。

璇歌 写了： 我现在遇到这个问题袄。 黑死我.....
“显示服务器” 这个翻译搞得，挺吓人的。

木木结 写了：晕哦，我刚才又遇到了，，，我已经是第二次遇到了。。。

pinper 写了：你用的是9.10的版本吗，这个应该是gnome和X服务器之间配合的一个问题，导致gnome的电源管理非正常的认为你已经处于空闲状态了开始挂起系统，显示器就黑屏了，写文章的人认为解决问题的彻底方案是修改X服务器，同时修改gnome的电源管理部分，并且已经有修改方法了，看看用的是ubuntu什么版本，不是最新版本的话可以升级到最新的看看，实在不行就修改一下电源管理方案，任何时候都不睡眠，试试看