[ALSA - driver 0000425]: usb-usx2y: System lockup on PCM device open (OHCI)

[bugtrack@alsa-project.org]

A BUGNOTE has been added to this bug.
======================================================================
https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000425
======================================================================
Reported By:                rncbc
Assigned To:                karsten
======================================================================
Project:                    ALSA - driver
Bug ID:                     425
Category:                   USB - usb-usx2y
Reproducibility:            always
Severity:                   block
Priority:                   normal
Status:                     assigned
Distribution:               Mandrake 10.0 Official
Kernel Version:             2.6.8-rc2
======================================================================
Date Submitted:             08-06-2004 10:53 CEST
Last Modified:              09-26-2004 22:18 CEST
======================================================================
Summary:                    usb-usx2y: System lockup on PCM device open (OHCI)
Description: 
As of ALSA 1.0.6rc1, the US-x2y PCM device driver module exposes a hard
conflict on OHCI based USB controllers, causing a complete system lockup
-- kernel oops on an interrupt handler -- exactly upon starting or
openning the PCM device for audio playback. 
======================================================================

----------------------------------------------------------------------
 rncbc - 08-06-2004 12:16 CEST 
----------------------------------------------------------------------
Just to add, that this issue does not occur as of previous
alsa-driver-1.0.5a, same platform, kernel or hardware. Seems to have been
introduced on CVS semewhere since mid-July. Something about "no sleeping"
in ALSA's pcm START/STOP callbacks, but no sure.

----------------------------------------------------------------------
 karsten - 09-23-2004 20:52 CEST 
----------------------------------------------------------------------
that seams to have something to do with a threaded IRQ10?
Does it also happen with hardirq_preempting off?
Please geneate oops traces from the 2.6.9-rc2-mmx-Sy kernel also. 
If those traces also happen in non usx2y-module area,
find out, which snd_*() call triggers the oops.
Check wether it happens if you disable hyperthreads.
Erm, did I fail to include some important errorchecks after calling
kernel/usb functions?
Run with at least ALSA debug options enabled. Other kernel debug options
may help too.

----------------------------------------------------------------------
 rncbc - 09-24-2004 09:43 CEST 
----------------------------------------------------------------------
Please note that this problem is not related to the voluntary-preempt
kernel patch nor is SMP/HT related. The machine where its beeing exposed
is a Compaq Presario 2516EA (laptop), P4 2.533GHz (UP, no-HT enabled).

Also FWIW, it doesn't matter if ACPI is enabled or not. The point where
the kernel oops occurs seems to be always under ohci_hcd (see
hard-screenshot).

----------------------------------------------------------------------
 rncbc - 09-25-2004 17:18 CEST 
----------------------------------------------------------------------
Now using 2.6.9-rc2-mm3-S6 (voluntary-preempt).

One thing I've noticed, but just related to VP, is that while having
hardirq-preempt=1 and /proc/irq/10/ohci_hcd/threaded=1, the kernel
doesn't
crash when opening the PCM hw device (either via jackd or aplay). But
still useless or zombie anyway. It does crash however when I unplug my
US-224 (switch its power down).

With hardirq-preempt=0 or /proc/irq/10/ohci_hcd/threaded=0, I get the
same
old bad behavior: a kernel oops somewhere on the ohci_irq handling,
almost
immediately when the PCM device is open (e.g. by jackd or aplay). Yet
another screenshot added here (usx2y-oops4.png).

----------------------------------------------------------------------
 karsten - 09-26-2004 15:26 CEST 
----------------------------------------------------------------------
its always dl_done_list().
Please post unassembly of the oops.
Look in linux/Documentation/oops-tracing.txt.
Do:
$gdb /lib/modules/2.6.9-rc2-mm3-S6/kernel/usb/host/ohci_hcd.ko
$disassemble dl_done_list

Or find out the point up until evrything is still ok.
Calling snd_pcm_open from i.e. jackd's alsa or usx2y driver should not
harm anything as no usb_thingy is triggered, no?
That like snd_pcm_hw_params_*() should still be ok.
Most likely things crash in snd_pcm_prepare().

Place exit() calls or debug breaks before those alsa-lib calls. 
Step by step check corresponding snd_usb_usx2y functions:
Place return -EFAULT in those functions before usb subsystem calls.
Ok, erm sounds like complicated?

Mmh, there is this CONFIG_KEXEC kernel option.
http://marc.theaimsgroup.com/?i=<20040915125041.GA15450%20()%20in%20!%20ibm%20!%20com>
Could help if it already works.

Might also set a smaller console font to get more screen estate.
making visible alsa-debug statements being dumped immediately before the
oops.

Or get yourself a pcmcia rs232 card.

edited on: 09-26-04 15:26

----------------------------------------------------------------------
 rncbc - 09-26-2004 15:28 CEST 
----------------------------------------------------------------------
After some netconsole sessions, I have uploaded here the respective output
logs, which would be a bit more intelligible than the actual but
incomplete screenshots.

Both traces are from US-224 power up and firmware initial loads and then
the kernel oops that results from issuing just a simple aplay -D hw:1
somefile.wav.

netconsole.out.0.txt traces a session with all system modules loaded for a
full functional laptop; netconsole.out.1.txt results from a session
without pcmcia and ohci1394 related stuff loaded (and therefore saving
some irq claims).

Hope this eases the search for a solution :)

----------------------------------------------------------------------
 karsten - 09-26-2004 15:43 CEST 
----------------------------------------------------------------------
Please update all of alsa-kernel/usb from cvs head.
"Badness in usb_unlink_urb at drivers/usb/core/urb.c:457" should vanish.
Redo netconsole logs.

----------------------------------------------------------------------
 rncbc - 09-26-2004 22:00 CEST 
----------------------------------------------------------------------
Just uploaded netconsole.out.2.txt which is the result after updating to
full ALSA 1.0.7rc1 CVS (full update: alsa-kernel, alsa-driver, alsa-lib,
alsa-oss, alsa-tools, alsa-utils and alsa-firmware).

The ohci_hcd oops remains, but the badness on usb_unlink_urb has vanished,
as Karsten predicted.

Some other run-time info that someone might find useful:

-----------------------------------------------------------------
# uname -a

Linux lambda 2.6.9-rc2-mm3-S6.3 https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000001 Sun Sep 26 12:54:30 WEST 2004 i686
unknown unknown GNU/Linux

-----------------------------------------------------------------
# cat /proc/asound/version

Advanced Linux Sound Architecture Driver Version 1.0.7rc1.
Compiled on Sep 26 2004 for kernel 2.6.9-rc2-mm3-S6.3.

-----------------------------------------------------------------
# cat /proc/asound/cards

0 [A5451          ]: ALI5451 - ALI 5451
                     ALI 5451 at 0x1000, irq 5
1 [USX2Y          ]: USB US-X2Y - TASCAM US-X2Y
                     TASCAM US-X2Y (1604:8005 if 0 at 001/003)

-----------------------------------------------------------------
# grep . /proc/asound/*/*/xrun_debug

/proc/asound/A5451/pcm0c/xrun_debug:2
/proc/asound/A5451/pcm0p/xrun_debug:2
/proc/asound/card0/pcm0c/xrun_debug:2
/proc/asound/card0/pcm0p/xrun_debug:2
/proc/asound/card1/pcm0c/xrun_debug:2
/proc/asound/card1/pcm0p/xrun_debug:2
/proc/asound/USX2Y/pcm0c/xrun_debug:2
/proc/asound/USX2Y/pcm0p/xrun_debug:2

-----------------------------------------------------------------
# cat /proc/interrupts

           CPU0       
  0:     165578          XT-PIC  timer  0/65578
  1:        309          XT-PIC  i8042  1/309
  2:          0          XT-PIC  cascade  0/0
  5:          1          XT-PIC  ALI 5451  0/0
  8:          1          XT-PIC  rtc  0/1
  9:         21          XT-PIC  acpi  0/21
 10:       4760          XT-PIC  ohci_hcd, ohci_hcd, ohci1394, eth0 
0/4760
 11:          5          XT-PIC  yenta  5/5
 12:        114          XT-PIC  i8042  0/114
 14:       4156          XT-PIC  ide0  0/4156
 15:         11          XT-PIC  ide1  0/11
NMI:          0 
LOC:          0 
ERR:          0
MIS:          0

-----------------------------------------------------------------
# grep . /proc/irq/*/*/threaded

/proc/irq/10/eth0/threaded:1
/proc/irq/10/ohci1394/threaded:1
/proc/irq/10/ohci_hcd/threaded:0
/proc/irq/10/ohci_hcd/threaded:0
/proc/irq/11/yenta/threaded:1
/proc/irq/12/i8042/threaded:0
/proc/irq/14/ide0/threaded:1
/proc/irq/15/ide1/threaded:1
/proc/irq/1/i8042/threaded:0
/proc/irq/5/ALI 5451/threaded:0
/proc/irq/8/rtc/threaded:0
/proc/irq/9/acpi/threaded:1

-----------------------------------------------------------------
# grep . /sys/block/hd*/queue/max_sectors_kb

/sys/block/hda/queue/max_sectors_kb:16
/sys/block/hdc/queue/max_sectors_kb:16

-----------------------------------------------------------------
# grep . /proc/sys/kernel/*_preemption

/proc/sys/kernel/hardirq_preemption:1
/proc/sys/kernel/kernel_preemption:1
/proc/sys/kernel/softirq_preemption:1
/proc/sys/kernel/voluntary_preemption:1

----------------------------------------------------------------------
 karsten - 09-26-2004 22:18 CEST 
----------------------------------------------------------------------
erm, found the bug:
snd-usb-usx2y currently really can't cope with ohci,
as ohci_hcd doesn't use specified urb->start_frame values.
Only ISO_ASAP is supported and start_frame is 16Bit where
uhci start_frame is 10Bit.
... <bulb crackling> ...

Bug History
Date Modified  Username       Field                    Change              
======================================================================
08-06-04 10:53 rncbc          New Bug                                      
08-06-04 10:53 rncbc          File Added: usx2y-oops3.png                    
08-06-04 10:53 rncbc          Distribution              => Mandrake 10.0 Official
08-06-04 10:53 rncbc          Kernel Version            => 2.6.8-rc2       
08-06-04 12:16 rncbc          Bugnote Added: 0001538                       
09-23-04 20:52 karsten        Bugnote Added: 0001849                       
09-24-04 09:43 rncbc          Bugnote Added: 0001858                       
09-25-04 17:13 rncbc          File Added: usx2y-oops4.png                    
09-25-04 17:18 rncbc          Bugnote Added: 0001911                       
09-25-04 17:45 karsten        Bugnote Added: 0001912                       
09-26-04 14:54 karsten        Bugnote Edited: 0001912                      
09-26-04 15:15 rncbc          File Added: netconsole.out.0.txt                    
09-26-04 15:16 rncbc          File Added: netconsole.out.1.txt                    
09-26-04 15:26 karsten        Bugnote Edited: 0001912                      
09-26-04 15:28 rncbc          Bugnote Added: 0001921                       
09-26-04 15:43 karsten        Bugnote Added: 0001922                       
09-26-04 21:52 rncbc          File Added: netconsole.out.2.txt                    
09-26-04 22:00 rncbc          Bugnote Added: 0001925                       
09-26-04 22:18 karsten        Bugnote Added: 0001927                       
======================================================================


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