[mythtv-users] Odd PVR-350 FC2 Error: /dev/video0 Input/output Error

[Daniel Savard]

On Fri, 17 Sep 2004 09:06:33 -0400, vasudeva <vasudeva at megarad.com> wrote:
> Following Jarod Wilson's (very helpful) HOWTO, I built MythTV using
> Axel Thimm's kernel, myth and ivtv RPMs on Fedora Core 2 with kernel
> 2.6.8-1 with a PVR-350 video card, which I'm using as the TV-Out
> over component cables.  After some initial ivtv errors, I upgraded
> ivtv to ivtv-0.1.10-pre2-ck108o by hand, and am using the associated
> ivtvdev_drv.o in X.
> 
> I can read from /dev/video0 using dd and cat just fine.
> 
> However, as soon as I launch mythbackend, something happens to
> /dev/video0 that I can't read from it anymore.  Here's the
> mythbackend output.
> 

Check file permissions on the special file /dev/video0. The file is
probably not owned by the appropriate user. Are you using udev? Since
it's packaged with the FC2, I assume yes unless you migrate from
another version to FC2. In this case, since I haven't play with FC2, I
don't know if you had an option to keep your previous setup or you
were forced to switch to udev.  In short, is it a fresh new FC2
install or a migration from FC1 or RedHat?

> Starting up as the master server.
> 2004-09-15 17:50:33 mythbackend version: 0.16.20040906-1 www.mythtv.org
> 2004-09-15 17:50:33 Enabled verbose msgs : important general
> 2004-09-15 17:50:35 Found changes in the todo list.
> 2004-09-15 17:50:35 Scheduled 0 items in 0.357943 seconds.
> 2004-09-15 17:50:35 Seem to be woken up by USER
> 2004-09-15 17:52:42 MainServer::HandleAnnounce Playback
> 2004-09-15 17:52:42 adding: sputnik.sovietwar.org as a client (events: 0)
> 2004-09-15 17:52:42 MainServer::HandleAnnounce Playback
> 2004-09-15 17:52:42 adding: sputnik.sovietwar.org as a client (events: 0)
> 2004-09-15 17:52:42 MainServer::HandleAnnounce Playback
> 2004-09-15 17:52:42 adding: sputnik.sovietwar.org as a client (events: 1)
> 2004-09-15 17:52:42 MainServer::HandleAnnounce Playback
> 2004-09-15 17:52:42 adding: sputnik.sovietwar.org as a client (events: 0)
> 2004-09-15 17:52:42 adding: sputnik.sovietwar.org as a remote ringbuffer
> 2004-09-15 17:52:42 Changing from None to WatchingLiveTV
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> error reading from: /dev/video0
> read: Input/output error
> 
> Once I've launched mythbackend. I even get Input/output errors when
> trying to access /dev/video0 through dd or cat -- even if
> mythbackend isn't running anymore.  TO access /dev/video0 again, I
> have to reboot.
> 
> If I just load all the modules manually after a fresh reboot, I can
> indeed cat /dev/video0 > test.mpg and see a valid cable source.  I
> can also dd if=/dev/video0 of=/dev/video16 bs=64k and watch channel
> 3 on the X display on my TV screen.  For some reason, mythbackend messes
> something up with that device, and I can't figure out why.
> 
> My /etc/modprobe.conf:
> ***
> alias char-major-61 lirc_i2c
> alias eth0 3c59x
> alias snd-card-0 snd-emu10k1
> install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 &&
> /usr/sbin/alsactl restore >/dev/null 2>&1 || :
> remove snd-emu10k1 { /usr/sbin/alsactl store >/dev/null 2>&1 || : ;
> }; /sbin/modprobe -r --ignore-remove snd-emu10k1
> alias usb-controller uhci-hcd
> 
> # --- BEGIN: Generated by ALSACONF, do not edit. ---
> # --- ALSACONF verion 1.0.6 ---
> alias snd-card-0 snd-emu10k1
> alias sound-slot-0 snd-emu10k1
> # --- END: Generated by ALSACONF, do not edit. ---
> ***
> 
> (I originally had a lot more in there, but ckennedy's notes
> regarding his ivtv updates seem to dictate the above contents.
> I've tried it both ways, and get the same error either way.)
> 
> My /etc/modules.conf:
> ***
> path[toplevel]=/lib/modules/`uname -r`/updates
> # default path
> path[toplevel]=/lib/modules/`uname -r`
> # ivtv modules setup
> # This is for WinTV PVR-350 IVTV
> alias char-major-61 lirc_i2c
> alias char-major-81     videodev
> alias char-major-81-0   ivtv
> #alias char-major-81-1   bttv
> 
> options ivtv ivtv_debug=1 tuner=2
> #type=2 for NTSC only
> options saa7127 enable_output=1 output_select=0
> options msp3400 once=0 simpler=1 simple=0
> add below ivtv msp3400 saa7115 tuner saa7127
> add above ivtv lirc_dev lirc_i2c ivtv-fb
> post-install ivtv /usr/local/bin/ivtvctl -d /dev/video0 -u 0x3000
> ***
> 

the tuner=2 option is no longer required if you are using ivtv 0.1.10
as well as the options lines following the comment and the add and
post-install lines.

alias char-major-61 lirc_i2c
alias char-major-81     videodev
alias char-major-81-0   ivtv

Is all you need. The debug option is handy if you want more details on
what is going on, you can increase the debug level. But, your problem
seems not related to module loading at all.

> (I can also comment out everything but the aliases in modules.conf,
> and still get the odd mythbackend error...)
> 



-- 
-----------------
Daniel Savard