[ALSA - driver 0001726]: Front and Rear channels swap after first play when playing Surround40 on au8830

[bugtrack@alsa-project.org]

A NOTE has been added to this issue.
======================================================================
<https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1726> 
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Reported By:                Raymond
Assigned To:                mjander
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Project:                    ALSA - driver
Issue ID:                   1726
Category:                   PCI - au88x0
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Distribution:               Fedora Core 1
Kernel Version:             2.4.22-1.2199.nptl
======================================================================
Date Submitted:             01-08-2006 17:41 CET
Last Modified:              02-26-2006 13:28 CET
======================================================================
Summary:                    Front and Rear channels swap after first play when
playing Surround40 on au8830
Description: 
The front and rear channels are correct for playing Surround40 only at the
first time after the driver is loaded. 

The front and rear channels (Surround40) always swapped afterward using
speaker-test or xine. 

Playing stereo sound is OK.


 speaker-test -c4 -D hw:0,0
 
speaker-test 1.0.11rc2
 
Playback device is hw:0,0
Stream parameters are 48000Hz, S16_LE, 4 channels
Using 16 octaves of pink noise
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 2 to 8192
Period size range from 1 to 512
Periods = 4
Buffer time size 2525
To choose buffer_size = 8192
To choose period_size = 2048
was set period_size = 512
was set buffer_size = 8192
 0 - Front Left
 1 - Front Right
 3 - Rear Right
 2 - Rear Left
Time per period = 11.856821
 0 - Front Left
 1 - Front Right
 3 - Rear Right
 2 - Rear Left

======================================================================

----------------------------------------------------------------------
 ponchick - 02-26-06 07:22 
----------------------------------------------------------------------
I try to describe more cleanly:
1. Front/Rear swaps bug reproduced with any tool that use four channels
including speaker-test, aplay, xine and mplayer.
2. au88x0_surround40.patch fix this issue completly
3. There is another similar issue when channels swap almost randomly
(https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1726#0008085). It's
reproduced by speaker-test but I cannot reproduce
it with at least aplay and mplayer. au88x0_surround40.patch does not
affect the bug at all. If someone can reproduce it with any tool other
than speaker-test I think there should be separate bug report.
4. This bug is fixed and could be closed.

----------------------------------------------------------------------
 Raymond - 02-26-06 13:28 
----------------------------------------------------------------------
Is it feasible to use the hook to provide real "front" and "rear" devices
using 
pcm volume control https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1835 ?


http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html#pcm_plugins_hooks



      hooks.0 {
                type ctl_elems
                hook_args [
                        {
                                name "Sigmatel Surround Playback Switch"
                                preserve true
                                lock true
                                optional true
                                value [ 0 ]
                        }
                        {
                                name "PCM Playback Volume"
                                index { @func private_pcm_subdevice }
                                lock true
                                value [ 0 0 -48 -48]
                        }
                ]
        }

Issue History
Date Modified  Username       Field                    Change              
======================================================================
01-08-06 17:41 Raymond        New Issue                                    
01-08-06 17:41 Raymond        Distribution              => Fedora Core 1   
01-08-06 17:41 Raymond        Kernel Version            => 2.4.22-1.2199.nptl
01-27-06 16:45 Raymond        File Added: au88x0_surround40.patch               
    
02-04-06 06:26 Raymond        Note Added: 0007912                          
02-10-06 05:36 ponchick       Note Added: 0007987                          
02-10-06 06:32 Raymond        Note Added: 0007991                          
02-10-06 10:50 ponchick       Note Added: 0007998                          
02-10-06 11:25 Raymond        Note Added: 0008000                          
02-10-06 13:49 Raymond        Note Added: 0008003                          
02-10-06 13:56 Raymond        Note Edited: 0008003                         
02-12-06 07:48 Raymond        Note Edited: 0008003                         
02-12-06 10:12 Raymond        Note Edited: 0008000                         
02-16-06 05:37 ponchick       Note Added: 0008085                          
02-16-06 08:12 Raymond        Note Added: 0008088                          
02-16-06 10:12 Raymond        Note Added: 0008090                          
02-16-06 10:28 Raymond        Note Edited: 0008090                         
02-16-06 16:07 Raymond        Note Added: 0008097                          
02-17-06 03:35 ponchick       Note Added: 0008104                          
02-17-06 04:28 Raymond        Note Added: 0008105                          
02-17-06 04:35 Raymond        Note Edited: 0008105                         
02-17-06 05:56 Raymond        Note Edited: 0008105                         
02-17-06 06:09 Raymond        Note Edited: 0008105                         
02-26-06 07:22 ponchick       Note Added: 0008198                          
02-26-06 13:28 Raymond        Note Added: 0008200                          
======================================================================




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