[argyllcms] Re: argyllcms+colord

  • From: pdi <pdi@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 16 Dec 2015 14:44:07 +0200

On Tue, 15 Dec 2015 09:19:03 +1100
Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:

That should work. You should be able to see that the /dev/bus/usb
get put in the group set by the 55-Argyll.rules file.

@Graeme Gill

I think I identified what happens.

55-Argyll.rules, line 117, uses the existence
of /var/run/ConsoleKit/database as test for the use of udev-acl by the
system. If the file exists, it sets ACL_MANAGE=1.

Then, on line 121, gives group ownership to colord for all devices that
have ACL_MANAGE not set (ENV{ACL_MANAGE}!="*?").

As I wrote on my first mail, I use Slackware 14.1 which although it
uses ConsoleKit it compiles it *without* the switch --enable-udev-acl.
Nevertheless the file /var/run/ConsoleKit/database does exist. So the
rule on line 117 of 55-Argyll.rules sets ACL_MANAGE=1 for the
colorimeter, and the next rule on line 121 finds no device with
ACL_MANAGE unset, so it fails to change group ownership.

If, as a test, I change ENV{ACL_MANAGE}!="*?" to ENV{ACL_MANAGE}="*?" or
ENV{ACL_MANAGE}="", group ownership works fine.

I did a little search to see if I could find a more accurate test
for the use of udev-acl than the existence
of /var/run/ConsoleKit/database, but had no success.

As a side note, the upcoming release of Slackware substitutes ConsoleKit
with ConsoleKit2, and uses the compile switch --enable-udev-acl.

@Florian Höch
Thanks, it seems it is still relevant for already plugged-in devices.

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