[alsa-devel] snd_usb_caiaq bug?

[Marco Santamaria]

I applied the patch (or I think so...). I just removed the line:

dev->midi_out_substream = NULL;

from the function snd_usb_caiaq_midi_output_done in the file caiaq-midi.c.
Then I recompiled the driver.

The main issue is sorted out: I can start and shut down jackd without big
problems.

But with dmesg I still have the following message:

ALSA
/home/marco/build/linux-2.6.24-19-rt/alsa-1.0.17/driver-patched/alsa-driver-1.0.17/acore/rawmidi.c:196:
rawmidi drain error (avail = 4095, buffer_size = 4096)

Not sure if it is safe to ignore it.

Marco

2009/1/7 Takashi Iwai <tiwai at suse.de>

> At Sun, 4 Jan 2009 17:29:47 +0100,
> Marco Santamaria wrote:
> >
> > Hi,
> >
> > it's about one year that I'm using my Native Instruments Audio Kontrol 1
> > (USB2 audio/MIDI interface) only with audio applications and it has been
> > working well so far.
> > Now I'm trying to use it with Rosegarden (MIDI) and, as soon as I start
> > Rosegarden, JACK crashes, the process jackd becomes "uninterruptible" and
> > with the command dmesg I find the following new lines
> >
> > [ 1935.173876] BUG: unable to handle kernel NULL pointer dereference at
> > virtual address 00000044
> > [ 1935.173885] printing eip: f8a5f6fd *pde = 00000000
> > [ 1935.173891] Oops: 0000 [#1] PREEMPT SMP
> > [ 1935.173896] Modules linked in: isofs udf ipv6 af_packet i915 drm
> rfcomm
> > l2cap bluetooth ppdev acpi_cpufreq cpufreq_ondemand cpufreq_conservative
> > cpufreq_stats freq_table cpufreq_userspace cpufreq_powersave dock
> container
> > sbs sbshc iptable_filter ip_tables x_tables sbp2 parport_pc lp parport
> > snd_hda_intel snd_usb_caiaq snd_hwdep snd_pcm_oss snd_mixer_oss arc4
> > snd_seq_oss snd_pcm ecb blkcipher snd_seq_midi snd_page_alloc joydev
> > snd_rawmidi snd_seq_midi_event snd_seq iwl3945 sdhci serio_raw mmc_core
> > iwlwifi_mac80211 video output cfg80211 battery led_class ac snd_timer
> > snd_seq_device wmi_acer button snd evdev dcdbas iTCO_wdt
> iTCO_vendor_support
> > intel_agp shpchp pci_hotplug pcspkr soundcore agpgart psmouse ext3 jbd
> > mbcache sg sr_mod cdrom sd_mod b44 ata_generic ssb mii ohci1394 ieee1394
> > ata_piix pata_acpi libata scsi_mod ehci_hcd uhci_hcd usbcore thermal
> > processor fan fuse
> > [ 1935.173964]
> > [ 1935.173967] Pid: 1421, comm: IRQ-18 Not tainted (2.6.24-19-rt #1)
> > [ 1935.173970] EIP: 0060:[<f8a5f6fd>] EFLAGS: 00010292 CPU: 1
> > [ 1935.173979] EIP is at snd_rawmidi_transmit_peek+0x1d/0x100
> [snd_rawmidi]
> > [ 1935.173982] EAX: 00000000 EBX: f7106264 ECX: 0000003d EDX: f7106407
> > [ 1935.173985] ESI: ffffffea EDI: 00000000 EBP: f7106407 ESP: df85be38
> > [ 1935.173988]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
> > preempt:00000001
> > [ 1935.173991] Process IRQ-18 (pid: 1421, ti=df85a000 task=f7d45320
> > task.ti=df85a000)
> > [ 1935.173993] Stack: 0000003d 00000000 f7106264 00000000 00000000
> df83fc00
> > f8b8cc09 00000000
> > [ 1935.174000]        f7106264 f710630c 00000000 df83fc00 df83fc00
> f710630c
> > f888c888 00000008
> > [ 1935.174007]        df83fd08 00000000 f710630c f8870770 f728a0c0
> f728a0c0
> > ffffff8d f721e180
> > [ 1935.174014] Call Trace:
> > [ 1935.174021]  [<f8b8cc09>] snd_usb_caiaq_midi_send+0x29/0x80
> > [snd_usb_caiaq]
> > [ 1935.174034]  [<f888c888>] usb_hcd_giveback_urb+0x48/0xc0 [usbcore]
> > [ 1935.174064]  [<f8870770>] ehci_urb_done+0x70/0xb0 [ehci_hcd]
> > [ 1935.174075]  [<f887153f>] qh_completions+0x24f/0x430 [ehci_hcd]
> > [ 1935.174087]  [<f8870770>] ehci_urb_done+0x70/0xb0 [ehci_hcd]
> > [ 1935.174096]  [<f887293e>] ehci_work+0x51e/0x810 [ehci_hcd]
> > [ 1935.174103]  [<c010b1e3>] sched_clock+0x13/0x40
> > [ 1935.174116]  [<c0129199>] dequeue_task_rt+0xb9/0x1c0
> > [ 1935.174129]  [<f8875498>] ehci_irq+0x158/0x1c0 [ehci_hcd]
> > [ 1935.174142]  [<f888cb7b>] usb_hcd_irq+0x2b/0x60 [usbcore]
> > [ 1935.174166]  [<c016a9cc>] handle_IRQ_event+0x5c/0x100
> > [ 1935.174178]  [<c016b00a>] thread_simple_irq+0x4a/0x90
> > [ 1935.174185]  [<c016b959>] do_irqd+0x229/0x290
> > [ 1935.174194]  [<c016b730>] do_irqd+0x0/0x290
> > [ 1935.174199]  [<c0141fc2>] kthread+0x42/0x70
> > [ 1935.174203]  [<c0141f80>] kthread+0x0/0x70
> > [ 1935.174209]  [<c0105857>] kernel_thread_helper+0x7/0x10
> > [ 1935.174217]  =======================
> > [ 1935.174219] 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
> > [ 1935.174256] EIP: [<f8a5f6fd>] snd_rawmidi_transmit_peek+0x1d/0x100
> > [snd_rawmidi] SS:ESP 0068:df85be38
> > [ 1935.174265] ---[ end trace 9090d02b798b5496 ]---
> >
> > I already asked to the Rosegarden and JACK people, but they couldn't help
> > me: it seems to be a driver related problem,  as I can happily use
> > Rosegarden if I run JACK with the internal Intel sound card.
>
> How about the patch below?
>
>
> thanks,
>
> Takashi
>
> ---
> diff --git a/sound/usb/caiaq/caiaq-midi.c b/sound/usb/caiaq/caiaq-midi.c
> index 30b57f9..89a29f0 100644
> --- a/sound/usb/caiaq/caiaq-midi.c
> +++ b/sound/usb/caiaq/caiaq-midi.c
> @@ -170,7 +170,6 @@ void snd_usb_caiaq_midi_output_done(struct urb* urb)
>                return;
>
>        snd_rawmidi_transmit_ack(dev->midi_out_substream, buf[2]);
> -       dev->midi_out_substream = NULL;
>        snd_usb_caiaq_midi_send(dev, dev->midi_out_substream);
>  }
>
>