Alsa: Do not open device twice in QSoundEffect

When either QSoundEffect::loadedChanged or QSoundEffect::statusChanged is emitted
QSoundEffect::play() can be called which results to call QAudioOutput::start() twice.

Added a fix to call QAudioOutput::start() only if QAudioOutput::state() is QAudio::StoppedState.

Flow trace:
1. PrivateSoundSource::sampleReady()
2. QSoundEffectPrivate::setStatus(QSoundEffect::Ready)
   and emits statusChanged() or loadedChanged()
3. If there is a connection to QSoundEffect::loadedChanged/statusChanged
   and QSoundEffect::play() is called there.
4. QSoundEffect::play() calls QAudioOutput::start() because sample is ready
5. QAudioOutput::start() is called again within PrivateSoundSource::sampleReady()
   when QSoundEffectPrivate::setStatus exited.

Change-Id: I7ad8e9126b6006e1972356c80a7fd2e5c6a5ea04
Reviewed-by: Andy Shaw <andy.shaw@qt.io>
Reviewed-by: Christian Stromme <christian.stromme@qt.io>

0 files changed, 0 insertions, 0 deletions