Hi, I've just bought a Native Instruments Audio Kontrol 1 as well recently. I guess the problem resides in the caiaq driver that all cited models share.
The following thread was of great help for the first attempts to have it working even with non-jackable apps: <http://www.native-instruments.com/forum/showthread.php?t=53898> If you set up your .asoundrc file as defined at the bottom of the 2nd page, you can select within Mixxx another ALSA device called "usb", but it introduces a huge latency, and mixxx might eventually crash. plughw:1,0,0 is recommended instead of hw:1,0,0 (with a variable ID depending on your wiring) for simple audio players (with no realtime issues, ex aplay), as it is as well the only solution to have them work. The crash is easy to reproduce: you simply have to open the mixxx sound preferences and choose your Native Instruments device. It occurs as well when you try to shutdown your jack server, if previously successfully started on the device. The mouse moves and keystrokes become jittery and slow. Here follows a dmesg snippet right from after a crash on Ubuntu 8.04 2.6.24-21-rt #1 SMP PREEMPT RT i686. I guess the most interesting part is located at the end close to "rawmidi drain error". From this clue, I suspected the MIDI part of the driver. Might be dumb, but I tried setting up another MIDI device in the mixxx MIDI controller settings, but it didn't prevent it from crashing. I tried to unload the rawmidi module, but it is required by the caiaq module. [ 1792.614751] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000044 [ 1792.614761] printing eip: f8bc06fd *pde = 00000000 [ 1792.614767] Oops: 0000 [#1] PREEMPT SMP [ 1792.614771] Modules linked in: snd_rtctimer ipv6 i915 drm af_packet rfcomm l2cap ppdev acpi_cpufreq cpufreq_powersave cpufreq_stats cpufreq_userspace cpufreq_conservative cpufreq_ondemand freq_table container sbs sbshc bay dock iptable_filter ip_tables x_tables nls_iso8859_1 nls_cp437 vfat fat aes_i586 dm_crypt dm_mod ipaq usbserial parport_pc lp parport snd_seq_dummy snd_usb_caiaq snd_seq_oss snd_seq_midi arc4 ecb snd_rawmidi blkcipher snd_seq_midi_event snd_pcm_oss snd_mixer_oss snd_seq snd_pcm joydev snd_seq_device video output ac battery snd_timer usbhid hid iwl3945 hci_usb iwlwifi_mac80211 psmouse bluetooth cfg80211 serio_raw snd tpm_infineon asus_laptop tpm tpm_bios led_class button soundcore evdev snd_page_alloc pcspkr iTCO_wdt iTCO_vendor_support intel_agp shpchp pci_hotplug agpgart ext3 jbd mbcache usb_storage sg sr_mod cdrom sd_mod ata_generic libusual ata_piix r8169 pata_acpi libata uhci_hcd ehci_hcd scsi_mod usbcore thermal processor fan fuse [ 1792.614845] [ 1792.614848] Pid: 2133, comm: IRQ-19 Not tainted (2.6.24-21-rt #1) [ 1792.614850] EIP: 0060:[<f8bc06fd>] EFLAGS: 00010292 CPU: 1 [ 1792.614859] EIP is at snd_rawmidi_transmit_peek+0x1d/0x100 [snd_rawmidi] [ 1792.614862] EAX: 00000000 EBX: f7df1264 ECX: 0000003d EDX: f7df1407 [ 1792.614864] ESI: ffffffea EDI: 00000000 EBP: f7df1407 ESP: f7139e38 [ 1792.614866] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 preempt:00000001 [ 1792.614869] Process IRQ-19 (pid: 2133, ti=f7138000 task=f7d580b0 task.ti=f7138000) [ 1792.614871] Stack: 0000003d 00000000 f7df1264 00000000 00000000 f77c6400 f8b97c79 00000000 [ 1792.614878] f7df1264 f7df130c 00000000 f77c6400 f77c6400 f7df130c f889e9a8 dfb45300 [ 1792.614884] f77c6508 00000000 f7df130c f88cb770 df9c92a0 df9c92a0 ffffff8d f730a480 [ 1792.614891] Call Trace: [ 1792.614896] [<f8b97c79>] snd_usb_caiaq_midi_send+0x29/0x80 [snd_usb_caiaq] [ 1792.614908] [<f889e9a8>] usb_hcd_giveback_urb+0x48/0xc0 [usbcore] [ 1792.614931] [<f88cb770>] ehci_urb_done+0x70/0xb0 [ehci_hcd] [ 1792.614940] [<f88cc53f>] qh_completions+0x24f/0x430 [ehci_hcd] [ 1792.614952] [<f88cd93e>] ehci_work+0x51e/0x810 [ehci_hcd] [ 1792.614958] [<c01224d8>] load_balance_fair+0xe8/0x120 [ 1792.614973] [<f88d0498>] ehci_irq+0x158/0x1c0 [ehci_hcd] [ 1792.614983] [<f889ec9b>] usb_hcd_irq+0x2b/0x60 [usbcore] [ 1792.615001] [<c016a8dc>] handle_IRQ_event+0x5c/0x100 [ 1792.615010] [<c016af1a>] thread_simple_irq+0x4a/0x90 [ 1792.615015] [<c016b869>] do_irqd+0x229/0x290 [ 1792.615023] [<c016b640>] do_irqd+0x0/0x290 [ 1792.615027] [<c0141ea2>] kthread+0x42/0x70 [ 1792.615030] [<c0141e60>] kthread+0x0/0x70 [ 1792.615034] [<c0105847>] kernel_thread_helper+0x7/0x10 [ 1792.615041] ======================= [ 1792.615042] Code: 24 10 83 c4 14 c3 bf ea ff ff ff eb e3 90 83 ec 18 89 74 24 0c be ea ff ff ff 89 6c 24 14 89 d5 89 5c 24 08 89 7c 24 10 89 0c 24 <8b> 58 44 8b 7b 04 85 ff 0f 84 8e 00 00 00 8d 43 20 31 f6 89 44 [ 1792.615078] EIP: [<f8bc06fd>] snd_rawmidi_transmit_peek+0x1d/0x100 [snd_rawmidi] SS:ESP 0068:f7139e38 [ 1792.615093] ---[ end trace a8aeb26563050901 ]--- [ 1802.651156] ALSA /usr/src/modules/alsa-driver/acore/rawmidi.c:196: rawmidi drain error (avail = 4095, buffer_size = 4096) [ 1824.378600] usb 1-7: reset high speed USB device using ehci_hcd and address 7 ++ C. ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Mixxx-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mixxx-devel
