Re: snd_mpu401_uart: hang when trying to play .mid

[Domen Puncer <domen@coderock.org>]

Found an easier way to reproduce: `echo 1 > /dev/midi` :-)

On 06/09/04 22:45 +0200, Takashi Iwai wrote:
> At Mon, 06 Sep 2004 16:18:25 -0400,
> Lee Revell wrote:
> > 
> > On Mon, 2004-09-06 at 14:58, Domen Puncer wrote:
> > > On 06/09/04 18:25 +0200, Takashi Iwai wrote:
> > > > At Mon, 6 Sep 2004 17:48:19 +0200,
> > > > Domen Puncer wrote: 
> > > > > On 06/09/04 17:18 +0200, Takashi Iwai wrote:
> > > > > > Does your hardware really a MPU401 device?

It has MIDI/Joystick port.

> > > > > > If not, you can remove the call of snd_mpu401_uart_new() in
> > > > > > snd_trident_probe().

This helps.

> Yes, indeed, the trident code is shared among several different chips
> (trident 4D DX, 4D NX and SI7018), and MPU401 handling seems hitting
> on SI7018 only.  I guess SI7018 is equipped mostly on laptops, which
> unlikely have MPU401 connectors.  So, removing the mpu401 support for
> SI7018 may be the simplest and safest solution.
> 
> Of course, we can track down the hang-up point (perhaps in the
> interrupt handler, snd_mpu401_uart_interrupt()) and fix it, too.

That would be nice.

I tried nmi_watchdog=1, but it didn't trigger on hang!?

Enabled sound debugging messages, added some printk's and got:

XXX: snd_mpu401_uart_output_open: 269
XXX: snd_mpu401_uart_cmd: 204
ALSA sound/drivers/mpu401/mpu401_uart.c:217: cmd: tx timeout (status = 0x50)
XXX: snd_mpu401_uart_cmd: 236
ALSA sound/drivers/mpu401/mpu401_uart.c:238: cmd: 0xff failed at 0x20 (status = 0xff, data = 0x1)
XXX: snd_mpu401_uart_cmd: 204
ALSA sound/drivers/mpu401/mpu401_uart.c:217: cmd: tx timeout (status = 0xff)
XXX: snd_mpu401_uart_cmd: 236
ALSA sound/drivers/mpu401/mpu401_uart.c:238: cmd: 0x3f failed at 0x20 (status = 0x3f, data = 0x1)
XXX: snd_mpu401_uart_output_trigger: 416
XXX: snd_mpu401_uart_add_timer: 164
XXX: snd_mpu401_uart_add_timer: 175
XXX: snd_mpu401_uart_output_write: 389
XXX: snd_mpu401_uart_remove_timer: 184
XXX: snd_mpu401_uart_remove_timer: 193
double fault, gdt at c1206260 [255 bytes]
NMI Watchdog detected LOCKUP on CPU0, eip c010e3b2, registers:
Modules linked in: ipv6 uhci_hcd ehci_hcd stv680 videodev ohci_hcd snd_trident snd_util_mem snd_mpu401_uart 8139too mii crc32
parport_pc ppdev parport snd_ens1371 snd_rawmidi snd_ac97_codec rtc
CPU:    0
EIP:    0060:[<c010e3b2>]    Not tainted VLI
EFLAGS: 00004002   (2.6.9-rc1-bk7-kjt2)
EIP is at doublefault_fn+0x42/0x110
eax: 0120625f   ebx: c1206260   ecx: c041acd8   edx: 0000406e
esi: 00000000   edi: 00000000   ebp: c04fd85c   esp: c04fd838
ds: 007b   es: 007b   ss: 0068
Unable to handle kernel NULL pointer dereference at virtual address 00000068
 printing eip:
c0118ab1
*pde = 00000000
Oops: 0000 [#1]
PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: ipv6 uhci_hcd ehci_hcd stv680 videodev ohci_hcd snd_trident snd_util_mem snd_mpu401_uart 8139too mii crc32
parport_pc ppdev parport snd_ens1371 snd_rawmidi snd_ac97_codec rtc
CPU:    0
EIP:    0060:[<c0118ab1>]    Not tainted VLI
EFLAGS: 00010017   (2.6.9-rc1-bk7-kjt2)
EIP is at do_page_fault+0x51/0x562
eax: c04ed000   ebx: c04fd000   ecx: 0000007b   edx: 00000000
esi: 00000000   edi: c0118a60   ebp: c04ed16c   esp: c04ed0cc
ds: 007b   es: 007b   ss: 0068
Process bash (pid: 3382, threadinfo=c04ec000 task=ca5e0a40)
Stack: 00000000 00000000 00000000 00000068 00000000 00000000 00000000 00030001
       00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
       00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Call Trace:
Stack pointer is garbage, not printing trace
Code: ff 21 e0 81 bd 6c ff ff ff ff ff ff bf 8b 10 c7 85 7c ff ff ff 01 00 03 00 89 95 70 ff ff ff 0f 87 bc 04 00 00 8b 95 70
ff ff ff <8b> 5a 68 8b 50 14 8b 00 81 e2 ff ff ff fb 8b 40 14 f7 d0 c1 e8
 <0>Kernel panic - not syncing: Fatal exception in interrupt

-----

Then i removed/added some printk's and got:

XXX: snd_mpu401_uart_output_open: 266
XXX: snd_mpu401_uart_cmd: 202
ALSA sound/drivers/mpu401/mpu401_uart.c:215: cmd: tx timeout (status = 0x50)
ALSA sound/drivers/mpu401/mpu401_uart.c:235: cmd: 0xff failed at 0x20 (status = 0x50, data = 0x0)
XXX: snd_mpu401_uart_cmd: 202
ALSA sound/drivers/mpu401/mpu401_uart.c:215: cmd: tx timeout (status = 0x50)
ALSA sound/drivers/mpu401/mpu401_uart.c:235: cmd: 0x3f failed at 0x20 (status = 0x50, data = 0x0)
XXX: snd_mpu401_uart_output_trigger: 413
XXX: snd_mpu401_uart_add_timer: 164
XXX: snd_mpu401_uart_output_write: 386
XXX: snd_mpu401_uart_timer: 146
XXX: snd_mpu401_uart_timer: 152
XXX: _snd_mpu401_uart_interrupt: 95
ALSA sound/drivers/mpu401/mpu401_uart.c:89: cmd: clear rx timeout (status = 0x50)
XXX: _snd_mpu401_uart_interrupt: 105
XXX: snd_mpu401_uart_output_write: 386
XXX: _snd_mpu401_uart_interrupt: 115
XXX: snd_mpu401_uart_timer: 146
XXX: snd_mpu401_uart_timer: 152
XXX: _snd_mpu401_uart_interrupt: 95
ALSA sound/drivers/mpu401/mpu401_uart.c:89: cmd: clear rx timeout (status = 0x50)
(last 7 lines seem to be repeating forever)

-----

Something else i could try?


	Domen


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