[arch-general] Kernel Module snd_seq_midi No Longer Inserted Automatically

[Steven Grace]

On 04/11/2015 01:17 AM, Ralf Mardorf wrote:
> On Fri, 10 Apr 2015 17:21:03 -0700, Steven Grace wrote:
>> Now I see that you're using an older kernel -- the problem apparently
>> started with kernel version 3.19. You're lucky you're not affected!
>
> Hi,
>
> this is what happens for
>
> [rocketmouse at archlinux ~]$ pacman -Si linux | grep Ver; uname -rm
> Version        : 3.19.3-3
> 3.19.3-3-ARCH x86_64
>
> [1]
>
> and
>
> [rocketmouse at archlinux ~]$ uname -rm
> 3.18.9-rt5-2-rt x86_64
>
> [2]
>
> So there seemingly is a serious issue on my machine too, but it's not
> related to snd_seq_midi, since it's not needed, as you can see by [2]
> before the USB devices are connected.
>
> Regards,
> Ralf
>
>
> [1]
> Indeed, with and without USB devices connected aconnect -i doesn't see
> my MIDI devices, neither the PCI/PCIe, nor the USB devices.
>
> Disconnected USB devices:
> [rocketmouse at archlinux ~]$ lsmod | grep midi
> snd_rawmidi            26806  2 snd_hdspm,snd_mpu401_uart
> snd_seq_device         13307  1 snd_rawmidi
> snd                    73436  12 snd_ice1712,snd_ac97_codec,snd_hdspm,snd_hwdep,snd_timer,snd_i2c,snd_pcm,snd_rawmidi,snd_ak4xxx_adda,snd_mpu401_uart,snd_seq_device,snd_cs8427
> [rocketmouse at archlinux ~]$ aconnect -i
> client 0: 'System' [type=kernel]
>      0 'Timer           '
>      1 'Announce        '
> client 14: 'Midi Through' [type=kernel]
>      0 'Midi Through Port-0'
>
> After connecting USB devices:
> [rocketmouse at archlinux ~]$ lsmod | grep midi
> snd_usbmidi_lib        27571  1 snd_usb_audio
> snd_rawmidi            26806  3 snd_hdspm,snd_usbmidi_lib,snd_mpu401_uart
> snd_seq_device         13307  3 snd_seq,snd_rawmidi,snd_seq_dummy
> snd                    73436  15 snd_ice1712,snd_usb_audio,snd_ac97_codec,snd_hdspm,snd_hwdep,snd_timer,snd_i2c,snd_pcm,snd_seq,snd_rawmidi,snd_usbmidi_lib,snd_ak4xxx_adda,snd_mpu401_uart,snd_seq_device,snd_cs8427
> usbcore               199382  9 uas,snd_usb_audio,usb_storage,ohci_hcd,ohci_pci,snd_usbmidi_lib,ehci_hcd,ehci_pci,usbhid
> [rocketmouse at archlinux ~]$ aconnect -i
> client 0: 'System' [type=kernel]
>      0 'Timer           '
>      1 'Announce        '
> client 14: 'Midi Through' [type=kernel]
>      0 'Midi Through Port-0'
>
>
> [2]
> Disconnected USB devices:
> [rocketmouse at archlinux ~]$ lsmod | grep midi
> snd_rawmidi            30863  2 snd_hdspm,snd_mpu401_uart
> snd_seq_device         14497  1 snd_rawmidi
> snd                    87720  12 snd_ice1712,snd_ac97_codec,snd_hdspm,snd_hwdep,snd_timer,snd_i2c,snd_pcm,snd_rawmidi,snd_ak4xxx_adda,snd_mpu401_uart,snd_seq_device,snd_cs8427
> [rocketmouse at archlinux ~]$ aconnect -i
> client 0: 'System' [type=kernel]
>      0 'Timer           '
>      1 'Announce        '
> client 14: 'Midi Through' [type=kernel]
>      0 'Midi Through Port-0'
> client 16: 'RME AIO_579bcc' [type=kernel]
>      0 'HDSPMx579bcc MIDI 1'
> client 20: 'TerraTec EWX24/96' [type=kernel]
>      0 'TerraTec EWX24/96 MIDI'
> client 24: 'TerraTec EWX24/96' [type=kernel]
>      0 'TerraTec EWX24/96 MIDI'
>
> After connecting USB devices:
> [rocketmouse at archlinux ~]$ lsmod | grep midi
> snd_usbmidi_lib        30258  1 snd_usb_audio
> snd_seq_midi           13564  0
> snd_seq_midi_event     14935  1 snd_seq_midi
> snd_seq                71606  3 snd_seq_midi_event,snd_seq_dummy,snd_seq_midi
> snd_rawmidi            30863  4 snd_hdspm,snd_usbmidi_lib,snd_mpu401_uart,snd_seq_midi
> snd_seq_device         14497  4 snd_seq,snd_rawmidi,snd_seq_dummy,snd_seq_midi
> snd                    87720  15 snd_ice1712,snd_usb_audio,snd_ac97_codec,snd_hdspm,snd_hwdep,snd_timer,snd_i2c,snd_pcm,snd_seq,snd_rawmidi,snd_usbmidi_lib,snd_ak4xxx_adda,snd_mpu401_uart,snd_seq_device,snd_cs8427
> usbcore               243361  9 uas,snd_usb_audio,usb_storage,ohci_hcd,ohci_pci,snd_usbmidi_lib,ehci_hcd,ehci_pci,usbhid
> [rocketmouse at archlinux ~]$ aconnect -i
> client 0: 'System' [type=kernel]
>      0 'Timer           '
>      1 'Announce        '
> client 14: 'Midi Through' [type=kernel]
>      0 'Midi Through Port-0'
> client 16: 'RME AIO_579bcc' [type=kernel]
>      0 'HDSPMx579bcc MIDI 1'
> client 20: 'TerraTec EWX24/96' [type=kernel]
>      0 'TerraTec EWX24/96 MIDI'
> client 24: 'TerraTec EWX24/96' [type=kernel]
>      0 'TerraTec EWX24/96 MIDI'
> client 28: 'USB Device 0x170b:0x11' [type=kernel]
>      0 'USB Device 0x170b:0x11 MIDI 1'
> client 32: 'nanoKONTROL' [type=kernel]
>      0 'nanoKONTROL MIDI 1'

Ralf, thanks for checking.

The problem with snd_seq_midi no longer being automatically added 
appears to be a kernel issue. The Arch bug report has been re-opened:
<https://bugs.archlinux.org/task/44286>

You indicate that snd_seq_midi is not important on your system. I'm 
guessing that perhaps you're using "raw" MIDI input instead of "seq".

I have a workaround and will monitor the bug report for a permanent 
resolution. Thanks to all who responded.