commit 9047d9b84e9d94d193e77abd81f5980eff77d73a
Author: Stephen Hurd <shurd@freebsd.org>
Date:   Thu Apr 14 19:11:01 2016 -0700

    ALSA: Call snd_pcm_drain() on suspend

    The ALSA plugin previously didn't suspend the ALSA device when the
    ::suspend() method is called.  This results in underrun errors when
    it's resumed.

    In ALSA, stopping a pcm doesn't close it, so the ALSA stop/start
    functions map to the QAudioInput suspend/resume functions.

    Change-Id: I2507065a1b7472af29eef70c531b9f6e8e5b3072
    Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

--- src/plugins/alsa/qalsaaudioinput.cpp
+++ src/plugins/alsa/qalsaaudioinput.cpp
@@ -701,6 +701,7 @@ qint64 QAlsaAudioInput::processedUSecs() const
 void QAlsaAudioInput::suspend()
 {
     if(deviceState == QAudio::ActiveState||resuming) {
+        snd_pcm_drain(handle);
         timer->stop();
         deviceState = QAudio::SuspendedState;
         emit stateChanged(deviceState);
--- src/plugins/alsa/qalsaaudiooutput.cpp
+++ src/plugins/alsa/qalsaaudiooutput.cpp
@@ -673,6 +673,7 @@ QAudioFormat QAlsaAudioOutput::format() const
 void QAlsaAudioOutput::suspend()
 {
     if(deviceState == QAudio::ActiveState || deviceState == QAudio::IdleState || resuming) {
+        snd_pcm_drain(handle);
         timer->stop();
         deviceState = QAudio::SuspendedState;
         errorState = QAudio::NoError;