Bug#572440: Reproduceable with Firefox and /dev/fd0

[Athanasius]

  This also affects Firefox, even when not using Gnome as desktop (I use
fvwm).

  I'm using Debian/testing on a system that does have a floppy disk
drive, but commonly no disk in the drive.  After bootup the first time
Firefox tries to put up the file selection dialogue (as when choosing
the location to save a download to) it hangs for ~25s.  This produces:

[ 4754.490418] end_request: I/O error, dev fd0, sector 0
[ 4766.680262] end_request: I/O error, dev fd0, sector 0

in dmesg output.

  Stopping dbus, exiting Firefox, starting dbus and restarting Firefox
will cause the problem to happen again on next file dialogue access.
'dbus-monitor --system' output (started just before Firefox):

07:44:38 0$ dbus-monitor --system
signal sender=org.freedesktop.DBus -> dest=:1.1 serial=2 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
   string ":1.1"
signal sender=org.freedesktop.DBus -> dest=(null destination) serial=7 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
   string ":1.2"
   string ""
   string ":1.2"
signal sender=org.freedesktop.DBus -> dest=(null destination) serial=8 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
   string ":1.3"
   string ""
   string ":1.3"
signal sender=org.freedesktop.DBus -> dest=(null destination) serial=9 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
   string ":1.4"
   string ""
   string ":1.4"
signal sender=org.freedesktop.DBus -> dest=(null destination) serial=10 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
   string ":1.5"
   string ""
   string ":1.5"
signal sender=org.freedesktop.DBus -> dest=(null destination) serial=4 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
   string "org.freedesktop.UDisks"
   string ""
   string ":1.5"
signal sender=org.freedesktop.DBus -> dest=(null destination) serial=7 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
   string ":1.6"
   string ""
   string ":1.6"
signal sender=:1.5 -> dest=(null destination) serial=8 path=/org/freedesktop/UDisks/devices/hda; interface=org.freedesktop.UDisks.Device; member=Changed
signal sender=:1.5 -> dest=(null destination) serial=9 path=/org/freedesktop/UDisks; interface=org.freedesktop.UDisks; member=DeviceChanged
   object path "/org/freedesktop/UDisks/devices/hda"
signal sender=:1.5 -> dest=(null destination) serial=27 path=/org/freedesktop/UDisks/devices/sda; interface=org.freedesktop.UDisks.Device; member=Changed
signal sender=:1.5 -> dest=(null destination) serial=28 path=/org/freedesktop/UDisks; interface=org.freedesktop.UDisks; member=DeviceChanged
   object path "/org/freedesktop/UDisks/devices/sda"

hda is the DVD drive, sda is the single SATA hard disk in the system.

Looking more closely with a 'tail -f /var/log/kern.log':

May  3 07:47:43 emilia kernel: [ 5127.707891] kobject: 'hda' (f0671c48): kobject_uevent_env
May  3 07:47:43 emilia kernel: [ 5127.707904] kobject: 'hda' (f0671c48): fill_kobj_path: path = '/devices/pci0000:00/0000:00:1c.4/0000:03:00.1/ide0/0.0/block/hda'
May  3 07:47:52 emilia kernel: [ 5137.506036] end_request: I/O error, dev fd0, sector 0
May  3 07:48:04 emilia kernel: [ 5149.695175] end_request: I/O error, dev fd0, sector 0

For this run I clicked 'Save as ...' on a link at 07:47:40.  As you can
see the DVD drive scan takes ~3 seconds, but that's acceptable.  What
isn't is the further ~20 seconds whilst it attempts to scan fd0 (OK,
it's only clearly 12 seconds above, but there'll be some attributeable
'hang time' before 07:47:52 for the first attempt as well).

  So, is there some way to disable this 'scanning' *without* disabling
the FDD entirely ?  Oh, I should note that although there is a line for
/dev/fd0 in /etc/fstab, it's commented out.

  One thing I need to check is if the FDD actually works at all.  A
quick test trying to mount or 'mdir' a floppy in it is showing no
activity.  I'll follow up when I've had chance to shutdown and check
connections.

-- 
- Athanasius = Athanasius(at)miggy.org / http://www.miggy.org/
                  Finger athan(at)fysh.org for PGP key
	   "And it's me who is my enemy. Me who beats me up.
Me who makes the monsters. Me who strips my confidence." Paula Cole - ME