/dev/snd/seq failed: no such file or directory

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

I’m working on an application that requires midi, but when I run the application I get this error:

ALSA lib seq_hw.c:466:(snd_seq_hw_open) open /dev/snd/seq failed: No such file or directory

MidiInAlsa::initialize: error creating ALSA sequencer client object.

It appears that the ALSA module that provides midi functionality (snd_seq) is not loaded.

I see the following potentially relevant modules:

./modules/4.9.140-tegra/kernel/sound/drivers/opl3/snd-opl3-lib.ko
./modules/4.9.140-tegra/kernel/sound/drivers/mpu401/snd-mpu401-uart.ko
./modules/4.9.140-tegra/kernel/sound/synth/snd-util-mem.ko
./modules/4.9.140-tegra/kernel/sound/pci/ymfpci/snd-ymfpci.ko
./modules/4.9.140-tegra/kernel/sound/pci/trident/snd-trident.ko
./modules/4.9.140-tegra/kernel/sound/pci/snd-intel8x0.ko
./modules/4.9.140-tegra/kernel/sound/pci/snd-atiixp.ko
./modules/4.9.140-tegra/kernel/sound/pci/oxygen/snd-oxygen-lib.ko
./modules/4.9.140-tegra/kernel/sound/pci/oxygen/snd-virtuoso.ko
./modules/4.9.140-tegra/kernel/sound/pci/nm256/snd-nm256.ko
./modules/4.9.140-tegra/kernel/sound/pci/snd-ad1889.ko
./modules/4.9.140-tegra/kernel/sound/pci/ac97/snd-ac97-codec.ko
./modules/4.9.140-tegra/kernel/sound/pci/snd-intel8x0m.ko
./modules/4.9.140-tegra/kernel/sound/pci/snd-atiixp-modem.ko
./modules/4.9.140-tegra/kernel/sound/pci/mixart/snd-mixart.ko
./modules/4.9.140-tegra/kernel/sound/pci/au88x0/snd-au8810.ko
./modules/4.9.140-tegra/kernel/sound/pci/emu10k1/snd-emu10k1x.ko

Can anyone point me to how I can get the right module loaded to have midi functionality on the Nano?

1 Like
2

For anyone else trying, I followed these instructions to rebuild the kernel, with the ALSA sequencer module enabled:

https://syonyk.blogspot.com/2019/04/nvidia-jetson-nano-desktop-use-kernel-builds.html

1 Like
3

I see The actual config kernel no compiled with snd midi support.

CONFIG_SOUND_OSS_CORE=y
ONFIG_SOUND_OSS_CORE_PRECLAIM=y
CONFIG_SND_SEQUENCER=y
CONFIG_SND_SEQ_DUMMY=y
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_SND_PCM_OSS_PLUGINS=y
CONFIG_SND_RAWMIDI_SEQ=y

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4

hi i am having issues with this as well, have spent about a day trying to figure out if there is any way to do this without editing and recompiling the kernel but as far as i can tell seems like no? either way the link in that blogspot to the kernel seems to be broken, i’m getting one from here https://developer.nvidia.com/embedded/linux-tegra in the link
L4T Driver Package (BSP) Sources for anyone else who needs to work on this. could be pretty handy for some folks if midi controller support came prebaked into os, any reason why it isn’t?

1 Like
5

This problem needs to edit kernel config. check this page.