[sane-devel] 3 mins delay at xscanimage startup due to querying hpiod

[Gerhard Jaeger]

On Dienstag, 6. März 2007, Volker Barth wrote:
> Dear all,
> 
> I recently bought my first scanner (Canon Lide 25), which is reported
> to work with the plustek backend. I'm running Kubuntu Dapper and have
> the most recent ubuntu binary packages 'libsane' and 'sane' installed.
> 
> My problem is that when I start xscanimage it takes 3:10 minutes until
> the GUI shows up, which is quite a while. After setting
> SANE_DEBUG_XSCANIMAGE to 4 I found that it stays all the time in the
> [init] section. Meanwhile, the syslog gives the following messages:
> 
>   scanimage: unable to open /var/run/hplip/hpiod.port: No such file or directory: prnt/hpijs/hplip_api.c 84

Why do you need that?

> when xscanimage is being started and when [init] has finished and the
> GUI shows up:  
> 
>   xscanimage: unable to connect hpiod socket 50000: Connection timed out: prnt/hpijs/hplip_api.c 703
>   xscanimage: ProbeDevices(): unable to send message: Bad file descriptor
> 
> Because of the first message I tried to start the hpiod daemon and
> hplip, although I did not understand why a Canon scanner on the
> plustek backend might require this daemon... The syslog told me:
> 
>   hpiod: 0.9.7 accepting connections at 45490... 
> 
> When starting xscanimage anew, the only improvement was that the first
> message complaining about the missing hpiod.port disappeared, but the
> rest remained very similar (after 190 seconds of waiting):
> 
>   xscanimage: unable to connect hpiod socket 45490: Connection timed out: prnt/hpijs/hplip_api.c 703 
>   xscanimage: ProbeDevices(): unable to send message: Bad file descriptor
> 
> This behaviour does not change even when I start xscanimage as
> root. In any case, after the GUI shows up, the scanner works
> apparently without problems, so it's only the looong delay that
> puzzles me.
> 
> My questions:
> - Why does xscanimage (or the KDE frontend kooka, or xsane, which I
>   all tried as well) try to connect to hpiod when there is apparently no
>   device present that depends on this daemon?

Probably because you've told SANE to do so. Find sane.d/dll.conf (in /etc/ or
/usr/local/etc) and check the entries. For the LiDE25 you'll only need 
plustek to be enabled, comment out all others (use #)

> - Is there a way to stop xscanimage to query the hpiod socket, or at
>   least to shorten the time it tries to connect to it?

s.o.

> - Do you think that compiling sane from source offers a chance to
>   circumvent this problem (e.g. because there is an option to build
>   sane without querying hpiod)?

Nope

- Gerhard