Merge this bug as it can affect performance :
https://github.com/OpenDingux/SDL/commit/e51100dce8da9099278dac9f5affbecf6396378b

--- a/src/audio/alsa/SDL_alsa_audio.c 
+++ b/src/audio/alsa/SDL_alsa_audio.c 
@@ -479,6 +479,10 @@
 		return(-1);
 	}
 
+	/* Switch to blocking mode for playback */
+	/* Note: this must happen before hw/sw params are set. */
+	SDL_NAME(snd_pcm_nonblock)(pcm_handle, 0);
+
 	/* Figure out what the hardware is capable of */
 	snd_pcm_hw_params_alloca(&hwparams);
 	status = SDL_NAME(snd_pcm_hw_params_any)(pcm_handle, hwparams);
@@ -611,9 +615,6 @@
 	}
 	SDL_memset(mixbuf, spec->silence, spec->size);
 
-	/* Switch to blocking mode for playback */
-	SDL_NAME(snd_pcm_nonblock)(pcm_handle, 0);
-
 	/* We're ready to rock and roll. :-) */
 	return(0);
 }