Brady Hunsaker Log of Computer Issues

I've often found the solution to computer problems I've encountered by searching the web and finding that someone else faced the same problem. I decided to keep this log in hopes that it may be useful to others.

The two main computers I use run Debian GNU/Linux unstable, so most of the issues refer to that distribution.

2006 Dec 17: GNU/Linux with a Canon Pixma MP530 Multi-function printer/scanner/copier/fax

I haven't posted in a while. It's not because there have been no challenges, but I've been a bit lazy and none of them have been major until this one.

My wife and I recently decided to replace our aging HP DeskJet 722C with a multifunction printer/scanner/copier/fax. I did some checking on reviews to see what was recommended and GNU/Linux compatible. We decided on a Canon Pixma MP530, which had good reviews on CNET.

But wait! It turns out my search for GNU/Linux compatibility was based on a printer driver available from TurboPrint. It was late at night and I did not realize that this is a non-free driver! I did not discover this error until I had unpacked the printer and tested the copying functions (which don't require the computer at all).

The good news: We have both the printer and scanner functions working without using the Turboprint driver. Here's what I did:

Printing functions

We were able to get good printing functionality using a driver available from the Canon Japan site. Several sites had recommended this for similar printers. I don't think it is completely free software, but I don't feel too bad using a GNU/Linux driver from the company.

  1. I downloaded the following files: I'm not sure whether the last one is really necessary.
  2. I ran alien filename.rpm to convert each of these to deb packages
  3. I ran dpkg -i filename.deb to install each of them.
  4. Among other things, this installs the file /usr/share/cups/model/canonmp500.ppd. I made a few edits to this file (as root), but I don't think any of them were necessary for correct functioning. I changed the default papersize to letter (required two line changes), and I added lines to allow resolutions of 1200x1200 and 2400x2400. I'm not sure whether these really work. I find that 600x600 is plenty good enough for my home printing purposes.
  5. Apparently, the Canon driver uses some older names for certain libraries. Following the advice from some other websites, I made a few symlinks: I'm not sure exactly which of these, if any, are necessary. I haven't tried experimenting with removing them.
  6. I connected the USB cable to the computer and restarted so that the printer would be detected. (Perhaps there's a way to avoid a full restart; I'm not sure.)
  7. I logged on to the web interface for CUPS at http://localhost:631/
  8. In the Administration tab, CUPS automatically saw the MP530 and asked if I wanted to add it. Actually it saw the printer twice. I added the one with the default name 'Canon_MP530_USB_1'. The driver was one of the options available; note that although the driver name is canonmp500, it seems to work fine with the MP530. If CUPS has trouble finding it, it's at /usr/share/cups/model/canonmp500.ppd.
  9. Try printing a test page to see if it works.

I actually had a little more trouble than this, mostly for unrelated reasons (I tried changing the name of the ppd file without fully understanding what I was doing). But now the printer seems to be working fine for me. I can even use the duplex feature! We have a Windows computer that accesses the printer through CUPS, and this works fine as well. (When I originally set this up for the old printer, I think I had to change a few CUPS configuration files to pass the 'raw' Windows communication directly to the printer. So I did have to install the Windows printer driver. It came on a CD with the printer.)

The only printing feature I would like to have is a CUPS option for grayscale mode. It may be possible to accomplish this by editing the PPD file, but I'm not sure. I may check more on that later.

Scanning

This was easier to sort out. The SANE project almost supports it out of the box. The support for the Canon Pixma MP530 comes from work done by Wittawat Yamwong.

The current version of the Debian unstable SANE package uses SANE 1.0.18. This didn't just work for me, though I expect that in a version or two it will 'just work' with the MP530.

Wittawat Yamwong has more up-to-date code than SANE currently uses. The SANE code (for Pixma support) comes from an older version of his code; as soon as they incorporate the newer version of his code I bet it will just work.

  1. I downloaded the code: I swear I got it directly from his site. The name was mp150-0.12.2.tar.bz2. But now (a few days later) his page says that the code should be accessed through the SANE CVS repository. I guess you'll have to try that.
  2. A simple 'make'.
  3. I don't think 'make install' is necessary, since SANE already has most of this (and used a Debian package to put it in the right place).
  4. The file that needs to be replaced is /usr/lib/sane/libsane-pixma.so.1 and I suppose /usr/lib/sane/libsane-pixma.so.1.0.18. Just copy the libsane-pixma.so file you just made to replace these two.
  5. Also, to make the permissions work, I added the following two lines to /etc/udev/libsane.rules:

    # Canon PIXMA MP530 SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="1712", MODE="664", GROUP="scanner"

  6. Make sure that any users who can use the scanner are in the 'scanner' group (which I think was added by SANE)
  7. Then try xsane. It should give you a choice of scanners that it detects. For me, it now detects the MP530 and works fine, both with the flatbed and with the ADF.

The only other feature that I wanted was the ability to scan legal documents. These won't fit in the flatbed, so the ADF is the only option. However, the sane-pixma backend has a fixed upper bound on height based on A4 size. To get around this, I went into the source code and changed the upper bound to an appropriate value for legal size (but left the default value). Then I could use scanadf with a command-line option for the height, and it works fine. I'm not going to put more details here, because I don't know whether there is a risk of physical damage if a large height value is sent for a flatbed scan. It would be nice if the SANE interface provided greater scanning heights for the ADF automatically.

Fax

I haven't tried faxing yet, but I don't think any computer support is necessary for direct faxes, which is all I plan on.

2006 May 27: IRQ issues during boot

I got lots of messages ending in "Disabling IRQ #11" during boot. There are lots of emails about this on various lists. A web search will reveal them (though the IRQ number varies). Apparently this issue started somewhere between kernels 2.6.8 and 2.6.12 (or something).

Without the "irqpoll" option, the boot would fail. With the "irqpoll" option, the boot succeeded, but I was still concerned. I thought it was related to the issue below, but now I don't think so.

Workaround: Disabling ACPI in the BIOS caused the messages to stop. I'm not sure exactly why; it is older hardware, so that could be contributing. This is a desktop machine, so I don't mind disabling ACPI.

2006 May 27: "cdrom_pc_intr: The drive appears confused"

I started getting lots of these messages in syslog from both my CD and DVD drives. There was no noticeable change in performance, but it bothered me nevertheless. Removing the ide-cd module caused the messages to stop, which I guess isn't surprising.

By removing hal, the messages stop, so apparently there is some problem with hal or hal's interaction with the kernel. Removing hal required that I remove gnome-volume-manager. This is acceptable for me. Hopefully the issue will be corrected in the future.

Workaround: Remove hal. This caused the boot-time names given to my drives to change, which required changes to /etc/fstab.

2006 May 05: Font problems using emacs in X

After a recent upgrade on a machine running Debian unstable, I found that most things worked fine, but emacs couldn't find fonts. Emacs running in the terminal was OK, but when it tried to create its own window, all the characters showed up as boxes.

It turned out that this is because of a major upgrade to X.org, which switched file locations to better conform to the FHS. Details are available on the Debian Wiki.

The solution in my case was to edit /etc/X11/xorg.conf and change the FontPath declarations to look in /usr/share/fonts/X11/.

Page last updated on 2006 May 27