Created attachment 20903 [details]
hal-device output

This bug was originally reported in Ubuntu at launchpad: https://bugs.launchpad.net/ubuntu/+source/hal/+bug/306014

hal version: 0.5.12~rc1
Ubuntu Jaunty (development release)

In Ubuntu performance of 3D graphics, like glxgears, has dropped significantly with libdrm 2.4.1. Investigation showed I did not have rw access to the DRM device /dev/dri/card0. Access rights were crw-rw----, owner root, group video.
I am not a member of the video group.

However, HAL is supposed to set an ACL on the DRM device. getfacl showed this was not done successfully.
$ sudo getfacl /dev/dri/card0
getfacl: Removing leading '/' from absolute path names
# file: dev/dri/card0
# owner: root
# group: video
user::rw-
group::rw-
other::---

Policy-kit showed console and active console should get access to the DRM device.
Console-kit showed a valid session for me.

Attached is the output of hal-find-by-capability --capability drm | xargs hal-device

/usr/share/hal/fdi/policy/10osvendor/20-acl-management.fdi contains:
    <match key="info.capabilities" contains="drm">
        <append key="info.capabilities" type="strlist">access_control</append>
        <merge key="access_control.file" type="copy_property">input.device</merge>
        <merge key="access_control.type" type="string">video</merge>
    </match>

(I found the same lines on git).
However, hal-device does not list the property input.device, so apparently the key access_control.file could not be set.

Replacing:
<merge key="access_control.file" type="copy_property">input.device</merge>
by:
<merge key="access_control.file" type="copy_property">linux.device_file</merge>

solved the problem for me. Now the ACL was applied and performance was back to normal:
$ sudo getfacl /dev/dri/card0
getfacl: Removing leading '/' from absolute path names
# file: dev/dri/card0
# owner: root
# group: video
user::rw-
user:albert:rw-
group::rw-
mask::rw-
other::---

I have an Intel GM965 Integrated Graphics Controller, pci-id 8086:2a02.
Kernel is 2.6.28-2-generic (based on 2.6.28-rc7). I got the same results with an older kernel, 2.6.27-7-generic.

NB: libdrm 2.4.1 is the first version in Ubuntu using udev. Older versions set permissions on /dev/dri/card0 in a different way.