Re: [alsa-devel] Crash 2.6.32.x, Echo 3G, Alsa, SCSI
From: F. Heitkamp
Date: Mon May 31 2010 - 15:12:14 EST
On 02/02/10 17:09, Giuliano Pochini wrote:
On Tue, 02 Feb 2010 16:30:27 +0100
Clemens Ladisch<clemens@xxxxxxxxxx> wrote:
Frederick V Heitkamp wrote:
Repeatable Hard Crash.
What else do I need to provide?
[ 5484.995249] WriteControlReg: not written, no change
[ 5485.069621] divide error: 0000 [#1] pcm_hw_params ok
[ 5485.070159] Prepare rate=44100 format=2 channels=2
[ 5485.070161] set_audio_format[14] = 5
[ 5485.070166] Prepare rate=44100 format=2 channels=2
[ 5485.070167] set_audio_format[14] = 5
[ 5485.070003] PREEMPT SMP
...
[ 5485.070003] EIP is at pcm_pointer+0x37/0x70 [snd_echo3g]
...
[ 5485.965788] [<c10041c0>] ? do_divide_error+0x0/0x90
[ 5485.980619] [<f87aa037>] ? pcm_pointer+0x37/0x70 [snd_echo3g]
[ 5485.998047] [<c104764e>] ? run_timer_softirq+0x17e/0x2e0
[ 5486.014175] [<f87ac9bf>] ? snd_echo_interrupt+0x11f/0x240 [snd_echo3g]
[ 5486.033940] [<c107a5d5>] ? handle_IRQ_event+0x45/0x190
bytes_to_frames() divides by runtime->frame_bits which is not set until
after the hw_params callback has succeeded, but the corresponding
chip->substream[] entry is set in that callback, by init_engine(). It
should probably have been set in the prepare callback.
I've just had another look at my code. Although it never happened to me, it
is indeed possible when hw_params() completes if another substream is
already running. The reason is that the card delivers an irq when it
executes an irq instruction in any of the running s-g lists. The irq
handler cannot know which substream caused it, so it has to call the
pointer() function for each of the configured substreams (ie. the ones
which completed one of the pcm_*_hw_params() callbacks.
There is another possible fix. I tested it briefly. It looks ok wrt race
conditions because pipe->state is set only in the trigger callback. I hope
I didn't overlook anything again...
Signed-off-by: Giuliano Pochini<pochini@xxxxxxxx>
--- alsa-driver-1.0.22.1/alsa-kernel/pci/echoaudio/echoaudio.c__orig 2010-02-02 22:37:33.000000000 +0100
+++ alsa-driver-1.0.22.1/alsa-kernel/pci/echoaudio/echoaudio.c 2010-02-02 22:44:03.000000000 +0100
@@ -1821,7 +1821,9 @@ static irqreturn_t snd_echo_interrupt(in
/* The hardware doesn't tell us which substream caused the irq,
thus we have to check all running substreams. */
for (ss = 0; ss< DSP_MAXPIPES; ss++) {
- if ((substream = chip->substream[ss])) {
+ substream = chip->substream[ss];
+ if (substream&& ((struct audiopipe *)substream->runtime->
+ private_data)->state == PIPE_STATE_STARTED) {
period = pcm_pointer(substream) /
substream->runtime->period_size;
if (period != chip->last_period[ss]) {
I've tried some newer kernels. Still having problems with the echo 3G.
This is kernel version:
2.6.32.13. The above patches posted to the linux kernel list seemed to
get rid of the crashes, but evidently did not go into the main kernel tree.
Any help appreciated. I am willing to help to the best of my ability.
Thanks!
Fred
This segment keeps looping to infinity:
[ 9331.528043] pcm_hw_free(0)
[ 9331.529200] free_pipes: Pipe 0
[ 9331.545230] pcm_hw_freed
[ 9331.552808] pcm_hw_freed
[ 9331.560365] pcm_close
[ 9331.567145] pcm_close oc=0 cs=1 rs=1
[ 9331.578595] pcm_close2 oc=0 cs=1 rs=0
[ 9490.665630] pcm_analog_out_open
[ 9490.675009] max_channels=6
[ 9490.683109] pcm_analog_out_open cs=1 oc=1 r=44100
[ 9490.698046] allocate_pipes: ch=0 int=2
[ 9490.702428] allocate_pipes: ok
[ 9490.718350] allocate_pipes()=0
[ 9490.727466] pcm_hw_params (bufsize=131072B periods=2 persize=65536B)
[ 9490.746450] SetSampleRate: 44100 clock d63
[ 9490.756870] WriteControlReg: Setting 0xd63, 0x3bfe
[ 9490.768468] WriteControlReg: not written, no change
[ 9490.787532] pcm_hw_params ok
[ 9490.796155] Prepare rate=44100 format=2 channels=2
[ 9490.810464] set_audio_format[0] = 5
[ 9490.820922] Prepare rate=44100 format=2 channels=2
[ 9490.835233] set_audio_format[0] = 5
[ 9490.845758] pcm_trigger start
[ 9490.847582] start_transport 1
[ 9497.317297] pcm_trigger stop
[ 9497.318517] stop_transport 1
[ 9497.334516] pcm_hw_free(0)
[ 9497.335483] free_pipes: Pipe 0
[ 9497.351709] pcm_hw_freed
[ 9497.359278] pcm_hw_freed
[ 9497.366836] pcm_close
[ 9497.373613] pcm_close oc=0 cs=1 rs=1
[ 9497.385061] pcm_close2 oc=0 cs=1 rs=0
[ 9503.442232] pcm_analog_out_open
[ 9503.451611] max_channels=6
[ 9503.459713] pcm_analog_out_open cs=1 oc=1 r=44100
[ 9503.474663] allocate_pipes: ch=0 int=2
[ 9503.484394] allocate_pipes: ok
[ 9503.494962] allocate_pipes()=0
[ 9503.504081] pcm_hw_params (bufsize=131072B periods=2 persize=65536B)
[ 9503.523069] SetSampleRate: 44100 clock d63
[ 9503.532174] WriteControlReg: Setting 0xd63, 0x3bfe
[ 9503.545805] WriteControlReg: not written, no change
[ 9503.564143] pcm_hw_params ok
[ 9503.572765] Prepare rate=44100 format=2 channels=2
[ 9503.587074] set_audio_format[0] = 5
[ 9503.597490] Prepare rate=44100 format=2 channels=2
[ 9503.611839] set_audio_format[0] = 5
[ 9503.622355] pcm_trigger start
[ 9503.623236] start_transport 1
[ 9510.095872] pcm_trigger stop
[ 9510.096578] stop_transport 1
[ 9510.113193] pcm_hw_free(0)
[ 9510.114163] free_pipes: Pipe 0
[ 9510.130405] pcm_hw_freed
[ 9510.137982] pcm_hw_freed
[ 9510.145541] pcm_close
[ 9510.152317] pcm_close oc=0 cs=1 rs=1
--
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