Re: [Denemo-devel] cat /dev/midi has stopped working!

[Richard Shann]

On Wed, 2008-11-05 at 16:54 -0600, Jeremiah Benham wrote:
> stopping alsa? If alsa is set up correctly and your system provides it
> alsa can be restarted from then init scripts. 
> 
> > How do I debug this situation?
> 
> I would first unplug it. reboot. Once it is fully booted up do this in
> a
> termianal:
> 
> dmesg | tail -f
> 
> then plug it in. see what it says. 
plugged in I get

usb 3-2: new full speed USB device using uhci_hcd and address 2
usb 3-2: configuration #1 chosen from 1 choice
eth0: no IPv6 routers present
usb 3-2: USB disconnect, address 2
usb 3-2: new full speed USB device using uhci_hcd and address 3
usb 3-2: configuration #1 chosen from 1 choice

when I unplug it I get

usb 3-2: USB disconnect, address 2
usb 3-2: new full speed USB device using uhci_hcd and address 3
usb 3-2: configuration #1 chosen from 1 choice
usb 3-2: USB disconnect, address 3


> You might want to also try:
> 
> dmesg | grep hotplug
> 
$ dmesg | grep hotplug
pci_hotplug: PCI Hot Plug PCI Core version: 0.5


> to make sure it truly started. I remember a few times I thought
> hotplug
> was running but it wasn't. 
> 
> Whats in your /dev/snd/ if you see midi devices in there more than
ls /dev/snd
 
$ ls /dev/snd
controlC0  midiC1D0  pcmC0D0p  pcmC0D1p  timer
controlC1  pcmC0D0c  pcmC0D1c  seq


> likely one of them is your keyboard. 
> 
> What does lsmod tell you. 
lsmod
Module                  Size  Used by
uhci_hcd               20236  0
snd_usb_audio          68448  0
snd_usb_lib            14592  1 snd_usb_audio
snd_hwdep               8836  1 snd_usb_audio
speedstep_lib           4612  0
freq_table              4484  0
ppdev                   8708  0
lp                     10948  0
button                  6800  0
ac                      5252  0
battery                 9732  0
ipv6                  213984  8
dm_snapshot            15644  0
dm_mirror              18000  0
dm_mod                 48952  2 dm_snapshot,dm_mirror
loop                   14216  0
snd_via82xx            25368  1
gameport               13832  1 snd_via82xx
snd_ac97_codec         82848  1 snd_via82xx
snd_ac97_bus            2432  1 snd_ac97_codec
snd_pcm_oss            38048  0
snd_mixer_oss          15232  1 snd_pcm_oss
tsdev                   7616  0
snd_pcm                65928  4
snd_usb_audio,snd_via82xx,snd_ac97_codec,snd_pcm_oss
snd_page_alloc         10248  2 snd_via82xx,snd_pcm
snd_mpu401_uart         7552  1 snd_via82xx
snd_seq_dummy           3972  0
snd_seq_oss            27648  0
snd_seq_midi            8352  0
snd_seq_midi_event      6784  2 snd_seq_oss,snd_seq_midi
snd_seq                42192  6
snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event
parport_pc             31524  1
serio_raw               6532  0
i2c_viapro              8340  0
snd_timer              19972  2 snd_pcm,snd_seq
snd_rawmidi            22048  3 snd_usb_lib,snd_mpu401_uart,snd_seq_midi
snd_seq_device          7820  5
snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq,snd_rawmidi
i2c_core               19472  1 i2c_viapro
floppy                 52004  0
via_ircc               22932  0
snd                    45412  15
snd_usb_audio,snd_hwdep,snd_via82xx,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_mpu401_uart,snd_seq_oss,snd_seq,snd_timer,snd_rawmidi,snd_seq_device
parport                32200  3 ppdev,lp,parport_pc
psmouse                34568  0
rtc                    11572  0
irda                  155836  1 via_ircc
shpchp                 32796  0
pci_hotplug            28088  1 shpchp
pcspkr                  2816  0
soundcore               8928  1 snd
crc_ccitt               2304  1 irda
via_agp                 9728  1
agpgart                29360  1 via_agp
evdev                   9088  1
ext3                  116360  1
jbd                    47272  1 ext3
ide_cd                 35616  0
cdrom                  32416  1 ide_cd
ide_disk               14848  3
via82cxxx               8452  0 [permanent]
generic                 4996  0 [permanent]
ide_core              107760  4 ide_cd,ide_disk,via82cxxx,generic
via_rhine              21768  0
mii                     5376  1 via_rhine
ehci_hcd               27144  0
usbcore               109444  5
uhci_hcd,snd_usb_audio,snd_usb_lib,ehci_hcd
thermal                13576  0
processor              23724  1 thermal
fan                     4868  0

> Hotplug if working correctly should be giving
> loading up the correct modules. 
All that looks ok. I have just tried:

ls /dev | fgrep midi
dmmidi1
midi1

and so I try 
cat /dev/midi1

and I get the midi data coming out. So whatever created /dev/midi for me
has stopped doing it (presumably it was a symbolic link to /dev/midi1
and somehow got deleted).
Thanks for the help - running through all that gave me the confidence to
look around some more.
Still no sign in the process table of any daemons working on behalf of
jack or alsa, so presumably this midi support comes from some other
packages.

$ ps aux | fgrep jack
rshann    6025  0.0  0.2   2828   548 pts/2    R+   08:19   0:00 grep -F
jack

$ ps aux | fgrep alsa
rshann    6030  0.0  0.2   2828   548 pts/2    R+   08:20   0:00 grep -F
alsa


Richard