ALSABackend: elaborate on start-up error cases

2 files changed, 21 insertions, 2 deletions

diff --git a/libs/backends/alsa/alsa_audiobackend.cc b/libs/backends/alsa/alsa_audiobackend.cc
index 7ce83ddc40..68f54fbe46 100644
--- a/libs/backends/alsa/alsa_audiobackend.cc
+++ b/libs/backends/alsa/alsa_audiobackend.cc
@@ -436,9 +436,17 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
 
 	unsigned int pos = _capture_device.find(" ");
 	_pcmi = new Alsa_pcmi (_capture_device.substr(0, pos).c_str(), _playback_device.substr(0, pos).c_str(), 0, _samplerate, _samples_per_period, _periods_per_cycle, 0);
+	switch (_pcmi->state ()) {
+		case 0: /* OK */ break;
+		case -1: PBD::error << _("AlsaAudioBackend: failed to open device.") << endmsg; break;
+		case -2: PBD::error << _("AlsaAudioBackend: failed to allocate parameters.") << endmsg; break;
+		case -3: PBD::error << _("AlsaAudioBackend: cannot set requested sample rate.") << endmsg; break;
+		case -4: PBD::error << _("AlsaAudioBackend: cannot set requested period size.") << endmsg; break;
+		case -5: PBD::error << _("AlsaAudioBackend: cannot set requested number of periods.") << endmsg; break;
+		case -6: PBD::error << _("AlsaAudioBackend: unsupported sample format.") << endmsg; break;
+		default: PBD::error << _("AlsaAudioBackend: initialization failed.") << endmsg; break;
+	}
 	if (_pcmi->state ()) {
-		// TODO get detailed error from _pcmi
-		PBD::error << _("AlsaAudioBackend: failed to open device (see stderr for details).") << endmsg;
 		delete _pcmi; _pcmi = 0;
 		return -1;
 	}
diff --git a/libs/backends/alsa/zita-alsa-pcmi.cc b/libs/backends/alsa/zita-alsa-pcmi.cc
index 8947e1a12e..10b8e08831 100644
--- a/libs/backends/alsa/zita-alsa-pcmi.cc
+++ b/libs/backends/alsa/zita-alsa-pcmi.cc
@@ -410,6 +410,7 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 		}
 	}
 
+	_state = -2;
 	if (_play_handle)
 	{
 		if (snd_pcm_hw_params_malloc (&_play_hwpar) < 0)
@@ -447,16 +448,19 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 		if (snd_pcm_hw_params_get_rate (_play_hwpar, &fsamp, &dir) || (fsamp != _fsamp) || dir)
 		{
 			if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't get requested sample rate for playback.\n");
+			_state = -3;
 			return;
 		}
 		if (snd_pcm_hw_params_get_period_size (_play_hwpar, &fsize, &dir) || (fsize != _fsize) || dir)
 		{
 			if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't get requested period size for playback.\n");
+			_state = -4;
 			return;
 		}
 		if (snd_pcm_hw_params_get_periods (_play_hwpar, &nfrag, &dir) || (nfrag != _nfrag) || dir)
 		{
 			if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't get requested number of periods for playback.\n");
+			_state = -5;
 			return;
 		}
 
@@ -503,6 +507,7 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 
 			default:
 				if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't handle playback sample format.\n");
+				_state = -6;
 				return;
 		}
 #elif __BYTE_ORDER == __BIG_ENDIAN
@@ -540,6 +545,7 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 
 			default:
 				if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't handle playback sample format.\n");
+				_state = -6;
 				return;
 		}
 #else
@@ -554,16 +560,19 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 		if (snd_pcm_hw_params_get_rate (_capt_hwpar, &fsamp, &dir) || (fsamp != _fsamp) || dir)
 		{
 			if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't get requested sample rate for capture.\n");
+			_state = -3;
 			return;
 		}
 		if (snd_pcm_hw_params_get_period_size (_capt_hwpar, &fsize, &dir) || (fsize != _fsize) || dir)
 		{
 			if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't get requested period size for capture.\n");
+			_state = -4;
 			return;
 		}
 		if (snd_pcm_hw_params_get_periods (_capt_hwpar, &nfrag, &dir) || (nfrag != _nfrag) || dir)
 		{
 			if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't get requested number of periods for capture.\n");
+			_state = -5;
 			return;
 		}
 
@@ -605,6 +614,7 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 
 			default:
 				if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't handle capture sample format.\n");
+				_state = -6;
 				return;
 		}
 #elif __BYTE_ORDER == __BIG_ENDIAN
@@ -636,6 +646,7 @@ void Alsa_pcmi::initialise (const char *play_name, const char *capt_name, const
 
 			default:
 				if (_debug & DEBUG_INIT) fprintf (stderr, "Alsa_pcmi: can't handle capture sample format.\n");
+				_state = -6;
 				return;
 		}
 #else