[Bug 1867] New: direct sound (wineoss) records when plays, generating dma overruns

[Wine Bugs]

http://bugs.winehq.com/show_bug.cgi?id=1867

Summary: direct sound (wineoss) records when plays, generating
                    dma overruns
           Product: Wine
           Version: 20030318
          Platform: All
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: wine-multimedia
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]
> From Jskud Sun Dec  7 14:33:12 -0800 2003

From: [e-mail]
To: [e-mail]
Subject: mystery solved: why bad/no sound with QuickTimePlayer on CX-plugin 2.0.2
Reply-to: [e-mail]

Problem

crappy sound with (latest) standard i810_audio driver

no sound with (latest) ALSA intel8x0 driver

Cause

i810_audio driver enables record and playback triggers on open;
    wineoss respects the current triggers; Intel ICH3 (the /dev/dsp
    controller) will read data on playback.  Since the client is not
    draining the input buffer, there is an overrun, and disruptive
    error handling, with poor real time audio behavior, ensues.

intel8x0: traced it as far as mmap failure (EIO) in wineoss.

Possible Solutions

Patch the i810_audio driver to disable PCM_ENABLE_INPUT on open

#if 0
    		dmabuf->trigger |= PCM_ENABLE_INPUT;
    	#endif
    
    Hack wineoss to disable the triggers on (device) open, since it
    carefully preserves them thereafter.

Use better hardware (Intel ICH5 does not exhibit this behavior)

Verification

Patched the i810_audio driver, and QuickTimePlayer works great.

Details

I recently purchased and installed Crossover Plugin 2.0.2, and
    installed the WinDoze QuickTime plugin (6.3, per the FAQ --
    thanks).  All this on my Dell Inspiron 4150, using a chipset
    with the Intel ICH3, running RedHat 8.0, with the latest kernel,
    2.4.20-24.8, installed.

There were no problems playing sound with xmms.  However, I had
    poor sound via QuickTimePlayer with the native i810_audio
    driver, so I installed the latest version of ALSA (1.0.0rc1),
    and configured the intel8x0 driver.  Worse, now I had no sound
    with QuickTimePlayer.

I enabled debug channels, and discovered that some mmap call in
    wineoss was failing with EIO when using ALSA.  But I also
    noticed I had "dma overrun" messages using the simpler
    (non-ALSA) default i810_audio, and decided to investigate that.

The Cause and Solution above report my findings.

/Jskud