Comment 34 for bug 356631

On Tue, Apr 21, 2009 at 09:25, Martin Pitt <email address hidden> wrote:
> However, this rule (and the corresponding code in cdrom_id [1]) relies
> on the track/session counts being zero if there is no CD in the drive.
> However, at least with kernel 2.6.28.8 the affected people get
> something like
>
>  ID_CDROM_MEDIA_STATE=blank
>  ID_CDROM_MEDIA_SESSION_NEXT=2894
>  ID_CDROM_MEDIA_SESSION_COUNT=19194
>  ID_CDROM_MEDIA_TRACK_COUNT=47323
>
> In other words, if ID_CDROM_MEDIA_STATE=blank, the session/track
> counts are not reliable.

Nice hardware! :)

> Arguably this could/should be fixed in the kernel, to fix these values
> to 0 if there is no CD in the drive, or it is blank. However, I
> wondered if the udev rules should be more robust in that regard, and
> not even ask for the number of tracks if there is no/empty CD.
> Affected people verified that adding this rule before the one from
> above makes things work:
>
>  KERNEL=="sr*", ENV{ID_CDROM_MEDIA_STATE}=="blank", GOTO="persistent_storage_end"

The problem is that there are other devices which report a blank media
for non-blank ones, so this rule would break these.

We changed it yesterday to use an ID_CDROM_MEDIA key:
  http://git.kernel.org/?p=linux/hotplug/udev.git;a=commit;h=f907449eee3f58fafafee0658e80578b1dbb2722

Would be good to know, if that works in the case you see the wrong values.

Thanks,
Kay