On an old laptop with Lubuntu 18.04, I have sisfb working properly. It's not blacklisted at all and loads on boot.

The problem is that sisfb is normally blacklisted in /lib/modprobe.d/fbdev-blacklist.conf. While I can comment that line out, whenever the udev package is updated using the weekly GUI update reminder, /lib/modprobe.d/fbdev-blacklist.conf is overwritten. While I can use chattr +i /lib/modprobe.d/fbdev-blacklist.conf to block the update from overwriting the file, that causes udev updates to fail, which causes apt full-upgrade to fail. Since the laptop is for the use of someone new to computers, this isn't a workable method.

How can I load sisfb properly during boot?


You can workaround this by creating simple bash script and running it via cron or add it as systemd unit.


SLEEP_TIME=30 # how often do the checks

while [ true ]; do

    SISFB_BL=`grep "blacklist sisfb" $BL`

    if [[ "$SISFB_BL" ]]; then

        # sisfb un-blacklist
        sed -i '/blacklist sisfb/d' /lib/modprobe.d/fbdev-blacklist.conf


        echo "[ ok ] sisfb blacklist not found"


    sleep $SLEEP_TIME


save it i.e. as /opt/sisfb_blacklist_watcher.sh

and add to cron on root:

sudo -i
crontab -e
@reboot /opt/sisfb_blacklist_watcher.sh &> /dev/null &

From ServerFault:

This answer:

apt-get install -o Dpkg::Options::="--force-confold" --force-yes -y udev

Read the comments below the answer though. It suggests --force-yes is sometimes an extreme option although it's not explained clearly.

An even better ServerFault answer is found here:

This Answer:

You can pass options to dpkg from apt. Interesting for you would be the option --force-confold. The command looks like this:

apt-get -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" upgrade

Setting --force-confdef as well makes apt-get still update the config file if it hasn't been edited, while --force-confold will keep edited configuration files without asking.

To make this permanent, you can also set these options in your apt.conf file:

Dpkg::Options {

Check e.g. http://debian-handbook.info/browse/wheezy/sect.package-meta-information.html#sidebar.questions-conffiles

  • Unfortunately, the udev package inscrutably doesn't consider that to be a configuration file (dpkg --status udev). I'll file a bug for that. – Chai T. Rex May 5 at 1:51
  • 1
    You would think anything ending in .conf should be respected as a configuration file and the industry standard rules should be followed. Perhaps a hook into shutdown / reboot scripts can run diff on current .conf file and saved copy. If different clobber the current file with saved good copy? – WinEunuuchs2Unix May 5 at 1:55
  • I've submitted a bug report. That's not a bad idea. I'll look into shutdown scripts for now and then use this answer if and when the bug is fixed. Thanks for your suggestions. – Chai T. Rex May 5 at 2:12

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