Fedora Core 6 Tryout, ACPI issues

Original date: November 8, 2006 8:59 AM by sonnik

Fedora Core 6 was released at the end of October. I was eager to switch back to FC after my tests with Ubuntu revealed that Ubuntu just wasn't for me. (I'm sure it's a fine distribution, but I had a few small issues that prevented me from getting used to it.) FC6 has the usual "Bleeding Edge" annoyances, but there was one that caused me to give up and go back to FC5.

I typically use my laptop to listen to some music, and I tend to like having the room dark at night. So, having the display power down or put to sleep when I'm not interfacing with the laptop is a blessing. This is a typical function of most modern operating systems. Display power management been working well in Linux for at least as many generations as I've been using Linux on a laptop.

Fedora Core 6 looks stunningly beautiful; these asthetics can be attributed mostly to some of the gdm/gnome themes available with the package. They've even taken the fact that many people have widescreen laptops into consideration, giving you desktop backgrounds at the correct 16x9 aspect ration. Unfortunately, I didn't get any screenshots for you.

As far as annoyances go, the default kernel installs to the i386 flavor. In and of itself, this isn't a real big issue. However, for whatever reason this kernel package doesn't seem to be able to handle CPU speed control. The Pentium M in my laptop will always run at full speed, requiring full power, generating more heat, requiring the fan to run more, which would deplete battery life much faster. I initially fixed this by compiling a custom kernel. However, I couldn't get my ipw2200 device to associate at this point. I didn't have a lot of time to spare for troubleshooting, fortunately a user at FedoraForum.org pointed out that the CPU speed control features worked in the stock i686 version of the kernel. I tested it out and the CPU speed did in fact work, along with my ipw2200 wireless device.

At this point, I was testing out my normal usage, when I learned that the backlight would shut off - and then turn back on. I tried out various combinations of gnome-power-manager, gnome-screensaver, and xscreensaver. I finally tried no screensaver or power management utility, and just tried X.org's xset utility to set DPMS parameters. Each of these worked, but sure enough, after anywhere from two to thirty seconds - the laptop's display backlight would power back on to a blank screen. Even a 'black' screen on a laptop can be an annoyance in a dark room.

I found a bugzilla report that I mentioned in this thread. Following the trail, I learned that the X.org software that shipped with FC6 treats any ACPI event as an 'input' to wake up the display. In my case, I suspect that although my laptop was running on AC power, even the natural battery discharge and recharge would cause the display to wake up. It appears as though they have a fix in place, but it probably won't be available as a Fedora package (rpm) file for some time.

Unfortunately, as seen here it looks like X.org's CVS access is kind of restricted and daily snapshots aren't currently offerred. As of the time of me writing this, Fedora hasn't released any updates beyond what has shipped with original distribution.

This issue is unfortunately a deal breaker for me; I won't be able to use Fedora Core 6. I understand the situation, however. These kinds of issues are to be expected when you look to the the latest and greatest releases. The thing that is unfortunate it that some users may be looking to test out Fedora Core and just assume this is a problem with the distribution as whole.

For the time being, I've reverted to FC5 with all the updates - which is still a great release. I'll give FC6 another shot in a few months.