Fix for Pisound's MIDI Input getting blocked for a while in rare cases.

There was a possible race condition which could lead to Input's FIFO queue to be underflown, causing high amount of processing in the worker thread for some period of time. Signed-off-by: Giedrius Trainavicius <[email protected]> (cherry picked from commit 1b94679a9b7f1e4ffce7369e466f151d40e481ec https://github.com/raspberrypi/linux raspi/rpi-4.15.y) Signed-off-by: Paolo Pisati <[email protected]> Signed-off-by: Seth Forshee <[email protected]>
sasikrishna2014 · Jul 18, 2018 · 6106d3f · 6106d3f
1 parent a685d37
commit 6106d3f
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/sound/soc/bcm/pisound.c b/sound/soc/bcm/pisound.c
@@ -56,6 +56,12 @@ static const char *pisnd_spi_get_version(void);
 static int pisnd_midi_init(struct snd_card *card);
 static void pisnd_midi_uninit(void);
 
+enum task_e {
+	TASK_PROCESS = 0,
+};
+
+static void pisnd_schedule_process(enum task_e task);
+
 #define PISOUND_LOG_PREFIX "pisound: "
 
 #ifdef PISOUND_DEBUG
@@ -129,7 +135,7 @@ static void pisnd_input_trigger(struct snd_rawmidi_substream *substream, int up)
 {
 	if (up) {
 		pisnd_spi_set_callback(pisnd_midi_recv_callback, substream);
-		pisnd_midi_recv_callback(substream);
+		pisnd_schedule_process(TASK_PROCESS);
 	} else {
 		pisnd_spi_set_callback(NULL, NULL);
 	}
@@ -258,10 +264,6 @@ static bool pisnd_spi_has_more(void)
 	return gpiod_get_value(data_available);
 }
 
-enum task_e {
-	TASK_PROCESS = 0,
-};
-
 static void pisnd_schedule_process(enum task_e task)
 {
 	if (pisnd_spi_device != NULL &&