SANE 1.0.13 mustek_pp CIS driver problems

This bug has been solved in version 1.0.14 of sane-backends.

Problem

Due to a change in the lower level communication routines in sane-backends 1.0.13, a serious bug in mustek_pp CIS driver has surfaced.

The symptoms are the following:

After one scan or preview scan,
- the scanner head does not return and
- the lamp stays on.
The head only returns when the scanning tool (xscanimage, xsane, kooka, ...) is restarted and a new scan is made. Making a second scan without restarting the tool is not possible.

Whether or not the problem shows up depends on you Linux distribution. Especially SuSE users seem to be affected.

In fact, if your distribution has a /dev/parport0 device entry (possibly created dynamically through devfsd), you are likely to be bitten by the bug.

Anyway, if you notice that the lamp stays on, unplug the power supply of the scanner for a few seconds. Leaving it on for a long time could damage your scanner (I have no prove of that, but it can't be very healthy to leave it on too long).

Solutions/workarounds

There are several possible workarounds:

Obviously, you can upgrade to sane-backends 1.0.14 or higher, either from source or in pre-compiled form.
If you are familiar with building packages from source and installing them, you can download these 2 source files: mustek_pp.c and mustek_pp_cis.c, which contain a fixed driver. To build a binary driver for your system with the fix, proceed as follows:
- Download and unpack the sane-backends-1.0.13.tar.gz source distribution from the SANE download page.
- In the directory sane-backends-1.0.13/backend, replace the files mustek_pp.c and mustek_pp_cis.c by the corrected files mentioned above.
- Configure, build, and install the package in the normal way:
  - ./configure
  - make
  - su -c "make install"
- Adapt the sane and mustek_pp configuration files (see the mustek_pp installation guide and the sane daemon installation tutorial).
NOTE: if you are currently using a pre-compiled binary SANE package (eg., an rpm), you must remove it first. Otherwise, chances are high that the original drivers and the drivers that you have built yourself will get mixed and that your problem will not be solved.
Alternatively, you can download the latest sane-backends CVS snapshot (see the SANE download page), which already contains the fixes, and build and install it in the same way as above.
If you are not familiar with building and installing software packages, you can try to download the following compiled driver: libsane-mustek_pp.so.1.0.13.gz

This driver has been compiled on a RedHat 7.2 system, but there is a big chance that it works on relatively recent versions of many other distributions too.

To check whether it can run on your system, do the following:
- gunzip libsane-mustek_pp.so.1.0.13.gz
- chmod 755 libsane-mustek_pp.so.1.0.13
- ldd libsane-mustek_pp.so.1.0.13
The last command should show something like this:
```
 
       libnsl.so.1 => /lib/libnsl.so.1 (0x40028000)
       libm.so.6 => /lib/i686/libm.so.6 (0x4003c000)
       libjpeg.so.62 => /usr/lib/libjpeg.so.62 (0x40060000)
       libieee1284.so.3 => /usr/lib/libieee1284.so.3 (0x4007f000)
       libdl.so.2 => /lib/libdl.so.2 (0x40089000)
       libc.so.6 => /lib/i686/libc.so.6 (0x4008c000)
       /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)
            
```
If you see a "=> ... not found ..." somewhere, you are out of luck. Then this option is not suited for you.

If everything is found, chances are high that this option will work for you. The only way to be sure, is to try it:

To install this driver, first find out where the current libsane-mustek_pp.so.1.0.13 one is installed. Most likely, you will find the file in /usr/lib/sane or /usr/local/lib/sane.
Become super-user (root), move the current driver out of the way and replace it by the one you downloaded:
- mv /usr/lib/sane/libsane-mustek_pp.so.1.0.13 /usr/lib/sane/libsane-mustek_pp.so.1.0.13.orig
- mv ./libsane-mustek_pp.so.1.0.13 /usr/lib/sane/
(Of course, in case the driver is located in /usr/local/lib/sane, the paths have to be adapted accordingly.)

To test the driver, become root and enter the following: scanimage -T
You can downgrade your sane-backends distribution to version 1.0.12, which doesn't have this problem. You may need to configure the sane daemon with root permissions, though (see the sane daemon installation tutorial).
The last option that you have, but which is also not guaranteed to work, is to rename or remove the /dev/parport0 entry. If you are using the SANE daemon, and it runs with root permissions, that may be all you need to do.

I cannot guarantee that will work or that nothing else will break, but it is worth a try if you are out of options otherwise.

If you have any questions or problems, you can always contact me at eddy_de_greef (at) tiscali (dot) be.

Last update: May 3, 2004

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