Shallow Thoughts

Akkana's Musings on Open Source, Science, and Nature.

Sat, 25 Aug 2007

Widescreen Monitor, Intel Graphics on Ubuntu

On a seemingly harmless trip to Fry's, my mother got a look at the 22-inch widescreen LCD monitors and decided she had to have one. (Can't blame her ... I've been feeling the urge myself lately.)

We got the lovely new monitor home, plugged it in, configured X and discovered that the screen showed severe vertical banding. It was beautiful at low resolutions, but whenever we went to the monitor's maximum resolution of 1680x1050, the bands appeared.

After lots of testing, we tentatively pinned the problem down to the motherboard. It turns out ancient machines with 1x AGP motherboards can't drive that many pixels properly, even if the video card is up to the job. Who knew?

Off we trooped to check out new computers. We'd been hinting for quite some time that it might be about time for a new machine, and Mom was ready to take the plunge (especially if it meant not having to return that beautiful monitor).

We were hoping to find something with a relatively efficient Intel Core 2 processor and Intel integrated graphics: I've been told the Intel graphics chip works well with Linux using open source drivers. (Mom, being a person of good taste, prefers Linux, and none of us wanted to wrestle with the proprietary nvidia drivers). We found a likely machine at PC Club. They were even willing to knock $60 off the price since she didn't want Windows.

But that raised a new problem. During our fiddling with her old machine, we'd tried burning a Xubuntu CD, to see if the banding problem was due to the old XFree86 she was running. Installing it hadn't worked: her CD burner claimed it burned correctly, but the resulting CD had errors and didn't pass verification. So we needed a CD burned. We asked PC Club when buying the computer whether we might burn the ISO to CD, but apparently that counts as a "data transfer" and their minimum data transfer charge is $80. A bit much.

No problem -- a friend was coming over for dinner that night, and he was kind enough to bring his Mac laptop ... and after a half hour of fiddling, we determined that his burner didn't work either (it gave a checksum error before starting the burn). He'd never tried burning a CD on that laptop.

What about Kinko's? They have lots of data services, right? Maybe they can burn an ISO. So we stopped at Kinko's after dinner. They, of course, had never heard of an ISO image and had no idea how to burn one on their Windows box. Fearing getting a disk with a filesystem containing one file named "xubuntu-7.04-alternate-i386.iso", we asked if they had a mac, since we knew how to burn an ISO there. They did, though they said sometimes the CD burner was flaky. We decided to take the risk.

Burning an ISO on a mac isn't straightforward -- you have to do things in exactly the right order. It took some fast talking to persuade them of the steps ("No, it really won't work if you insert the blank CD first. Yes, we're quite sure") and we had to wait a long time for Kinko's antivirus software to decide that Xubuntu wasn't malware, but 45 minutes and $10 later, we had a disc.

And it worked! We first set up the machine in the living room, away from the network, so we had to kill aptitude update when the install hung installing "xubuntu-desktop" at 85% (thank goodness for alternate consoles on ctl-alt-F2) but otherwise the install went just fine. We rebooted, and Xubuntu came up ... at 1280x1024, totally wrong. Fiddling with the resolution in xorg.conf didn't help; trying to autodetect the monitor with dpkg-reconfigure xorg crashed the machine and we had to power cycle.

Back to the web ... turns out that Ubuntu "Feisty" ships with a bad Intel driver. Lots of people have hit the problem, and we found a few elaborate workarounds involving installing X drivers from various places, but nothing simple. Well, we hadn't come this far to take all the hardware back now.

First we moved the machine into the computer room, hooked up networking and reinstalled xubuntu with a full network, just in case. The resolution was still wrong. Then, with Dave in the living room calling out steps off a web page he'd found, we began the long workaround process.

"First," Dave suggested, reading, "check the version of xserver-xorg-video-intel. Let's make sure we're starting with the same version this guy is."

dpkg -l xserver-xorg-video-intel ... "Uh, it isn't installed," I reported. I tried installing it. "It wants to remove xserver-xorg-video-i810." Hmm! We decided we'd better do it, since the rest of the instructions depended on having the intel, not i810, driver.

And that was all it needed! The intel driver autodetected the monitor and worked fine at 1680x1050.

So forget the elaborate instructions for trying X drivers from various sources. The problem was that xubuntu installed the wrong driver: the i810 driver instead of the more generic intel driver. (Apparently that bug is fixed for the next Ubuntu release.)

With that fix, it was only a few more minutes before Mom was happily using her new system, widescreen monitor and all.

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[ 13:23 Aug 25, 2007    More linux | permalink to this entry ]