11. Bugs

11.1 Machine-crashing Bugs

Bug

Machine fails to boot. Prints: kernel BUG at dcache.c. The is may be USB related. It happens to me, though not every time, when booting with a WUSB11 wireless plugged in.

Solution

As a temporary work-around, boot with the troublesome device(s) disconnected. Hopefully a future kernel will fix this problem.

Bug

AC97 sound can lock up machine. Certain sound files repeatably cause hard lock-ups when played with the intel i810 audio driver.

Solution

No known solution. It may be a hardware problem.

Bug

CDROM locks up machine if DMA is enabled.

Solution

If you find that your IDE controller/CDROM drive combination has this problem, use ``reconfig'' to turn off the DMA option for your CD drive. The default configuration is to have DMA on for DVD drives and off for CDROMs. ``Advanced configuration options'' on the first page must be checked, after which the DMA options will appear under Preferences.

Bug (FIXED)

Single processor machines (only?) freeze randomly when running the multi-processor kernel.

Solution

For older stand-alone machines, add the option apm=off to the append= line in /etc/lilo.conf. For network-booted machines, switch to the etherboot-2.4.18 or better kernel. For new installations, try un-checking the ``Blank screen with APM'' option in reconfig. Without this, many laptops may not be able to turn the backlight off though.

11.2 Application Bugs

Bug

Incomplete large (>2GB) file support. Packages diffutils, findutils, gzip, mkzftree are still lacking large file support. Also, mkisofs can generate CD/DVD images larger than 4GB, but none of the files on the image may exceed 2GB.

Solution

Use pipes if possible. For example, with gzip, gzip < infile > outfile will work, because bash does support large files. Eventually, some of these packages need to be upgraded (but with gzip, for example, the upgrade requires going to an alpha version.)

Bug (FIXED)

Turning off features in "reconfig" may not have an immediate effect.

Solution

Turning something new on works fine (if you say ``Yes'' to the ``Apply changes now?'' prompt.) If you've turned stuff off, you may want to reboot to be sure features really get turned off.

Bug

On ``reboot'', some computers seem to freeze instead of rebooting.

Solution

Hopefully you are near the computer and can just power-cycle it. Don't worry, the machine is properly shut down. The kernel just seems to have problems getting the BIOS to actually reset the machine. NOTE: You may have to hold the power switch for up to ten seconds to turn some computers off.

Bug

XEmacs complains that ``html-mode'' is not installed.

Solution

I don't know what html-mode is part of, but I installed hm--html-mode. Select that instead, after loading an HTML file, or look at the hm--html documentation for info on how to make it the default.

Bug

Mounting floppies and CD's requires cryptic commands and kernel modules.

Solution

Select the ``supermount'' options in reconfig.

NOTE: The PCMCIA CD support has been hacked to automatically mount the CD on /mnt/cdrom/ for you. Use the root menu in the Window Manager to eject the CD.

Bug (FIXED)

The glibc-2.2.3 nscd leaves core files in / sometimes.

Solution

This has been fixed by shutting down nscd differently.

Bug (FIXED)

The xntpd keeps running but stops adjusting the clock.

Solution

Switched to xntpd4. (There is a still a case where xntpd4 exits: If it successfully synchronized the clock, and then something else, maybe mplayer, messes with the real-time clock enough to offset the time by more than 1000 seconds ... xntpd will need to be re-started. An initial offset of 1000 seconds is not a problem.)

11.3 Laptop/PC Card Bugs

Bug

Screen blanks or laptop suspends while console is being remote-controlled by XTEST (x2x)

Solution

Set your X-Server to the XF86_ALL_CVS version, which includes a new patch that fakes console activity whenever X-Events are received through the XTEST protocol. The next stable X-Server release will include this patch.

Feature

After creating a user account, Netscape spins up the disk every few minutes.

Solution

Exit netscape and look for files history.dat and cookies.txt inside your .netscape or .mozilla directories. Move these files to /tmp/$USER/ (which is on a RAM disk) and make symbolic links at the old locations.

# cd .mozilla/default/*.slt/
# mv cookies.txt /tmp/$USER/ ; ln -s /tmp/$USER/cookies.txt .
# mv history.dat /tmp/$USER/ ; ln -s /tmp/$USER/history.dat .

This setup will also automatically clear all of your cookies each time you reboot.

Feature

The ssh client spins up the disk every time it starts

Solution

This is related to the X11-forwarding that the ssh client sets up; It touches a file called .Xauthority, by default in the home directory. Either relocate .Xauthority by setting the XAUTHORITY environment variable (the normal fvwm.xsession login script should do this for you, if you don't already have a .Xauthority in your home directory), or start ssh with the -x option if you do not need forwarding.

Feature

Software suspend (see section #s#>ec:sws) can sometimes take up to a couple of minutes to suspend.

Solution

Newer versions of swsusp may be better, but were not compatible with the 2.4.19 kernel. For now, just have patience if you use software suspend. Update: 2.4.26 software suspend is faster and seems more reliable.

Bug

Cisco aironet driver sometimes shows poor performance.

Solution

If you are far from the other receiver, make sure the transmit power (in reconfig, under Wireless IP) is at the maximum. ``Ping'' requests to the wireless gateway should typically return in about 3 ms. If this is not the case, put the laptop to sleep and wake it up again. This seems to work around the ``slow ping'' problem. Cause is still unknown.

Bug

Crash when coming out of suspend.

Solution

This is a very tricky thing. There are some kernel options (which must be chosen at compile time) that may help on some laptops and make things worse on others. If there is a PC Card plugged in, ejecting it first, or modifying /etc/apmd_proxy to eject it first for you may help.

Feature

Disk spins up when Emacs auto-saves and then sync's the disk.

Solution

If you want to live dangerously (no automatic backups in Emacs) then use the command `Meta-x auto-save-mode' (in every modified

are causing the disk to spin up, it can be difficult to track down the exact cause.

11.3.1 Sony Vaio laptop bugs

Bug

Sony Vaio's with built-in eepro100 ethernet can hang on warm reboot.

Solution

If this happens to you, power off completely ("cold boot") and Linux should come up properly. It is possible that this was fixed in 2.4.16.

Bug

Sony Vaio's hang half way through warm reboot if the PCMCIA CDROM was removed during reboot.

Solution

Same as above: power off completely and try again. This is probably a BIOS bug.

Bug

Some Vaio's lock up if screen is unblanked within 4 seconds of blanking.

Solution

Don't do that. (The SR series are apparently not affected.) This is almost definitely a BIOS bug.

Bug

Since pressing the power switch and closing laptop lid (on Vaio) can be used to suspend the laptop, doing both causes an extra suspend immediately after the first resume.

Solution

If you're going to close the lid anyway, don't suspend the laptop first. Let the action of closing the lid do that.