Arch Linux

dsdante

Member

Registered: 2014-12-04

Posts: 13

[WORKAROUND] Another MIDI issue in the kernel

Yesterday I plugged in a new USB MIDI keyboard (Axiom 61) - it worked fine, then I upgraded the kernel from 3.19.3-1 to 3.19.3-3. Today I checked the keyboard again, but it wasn't working anymore. It is listed in lsusb, but not in aconnect -i. The output of lsmod | grep usb is:

snd_usb_audio         149328  4 
snd_usbmidi_lib        27571  1 snd_usb_audio
snd_rawmidi            26806  1 snd_usbmidi_lib                                                
snd_hwdep              17244  2 snd_usb_audio,snd_hda_codec                                    
snd_pcm                88779  5 snd_usb_audio,snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_controller
snd                    73436  29 snd_hda_codec_realtek,snd_usb_audio,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_usbmidi_lib,snd_hda_codec,snd_hda_intel,snd_seq_device                                                                      
usbhid                 48596  0                                                                
hid                   110513  2 hid_generic,usbhid                                             
usbcore               199382  7 snd_usb_audio,ohci_hcd,ohci_pci,snd_usbmidi_lib,ehci_hcd,ehci_pci,usbhid
usb_common             12561  1 usbcore

(not exactly what is described in the wiki)

I tried downgrading the kernel back to 3.19.3-1, but it didn't solve the problem, so it could be a coincidence. The kernel was the only upgraded package.

Last edited by dsdante (2015-04-09 20:18:44)

satanselbow

Member

Registered: 2011-06-15

Posts: 538

Re: [WORKAROUND] Another MIDI issue in the kernel

Have you rebooted between kernel updates to refresh the loaded modules?

dsdante

Member

Registered: 2014-12-04

Posts: 13

Re: [WORKAROUND] Another MIDI issue in the kernel

Of course.

dsdante

Member

Registered: 2014-12-04

Posts: 13

Re: [WORKAROUND] Another MIDI issue in the kernel

Something weird is going here. I tried the following:

reboot
journalctl -f -p7
[opened a new shell]
lsmod |grep usb
lsusb
[turned the keyboard on]
lsusb
aconnect -i

and the keyboard has appeared. Then I tried exactly the same several times more, but no keyboard again.

Update: it works ~5% of tries. Maybe yesterday I just hit that try (another coincidence). I think the keyboard worked stable on another computer, need further investigation.

Last edited by dsdante (2015-04-09 10:11:59)

m0rph

Member

Registered: 2007-07-28

Posts: 26

Re: [WORKAROUND] Another MIDI issue in the kernel

https://bugs.archlinux.org/task/44286
Just load the snd_seq_midi kernel module

Last edited by m0rph (2015-04-09 20:12:48)

dsdante

Member

Registered: 2014-12-04

Posts: 13

Re: [WORKAROUND] Another MIDI issue in the kernel

m0rph, thanks! It'll do for now.