context: scale max_quantum and add quantum_limit

Also scale the max_quantum with the selected rate. Add a new
quantum_limit property that is the upper limit of the quantum regardless
of the sample rate, this is usually the allocated buffer size.

See #1931

src/daemon/client-rt.conf.in

@@ -9,6 +9,8 @@ context.properties = {
     #mem.allow-mlock = true
     #mem.mlock-all   = false
     log.level        = 0
+
+    #default.clock.quantum-limit = 8192
 }
 
 context.spa-libs = {

src/daemon/client.conf.in

@@ -9,6 +9,8 @@ context.properties = {
     #mem.allow-mlock = true
     #mem.mlock-all   = false
     log.level        = 0
+
+    #default.clock.quantum-limit = 8192
 }
 
 context.spa-libs = {

src/daemon/jack.conf.in

@@ -9,6 +9,8 @@ context.properties = {
     #mem.allow-mlock = true
     #mem.mlock-all   = false
     log.level        = 0
+
+    #default.clock.quantum-limit = 8192
 }
 
 context.spa-libs = {

src/daemon/pipewire-pulse.conf.in

@@ -9,6 +9,8 @@ context.properties = {
     #mem.allow-mlock = true
     #mem.mlock-all   = false
     #log.level       = 2
+
+    #default.clock.quantum-limit = 8192
 }
 
 context.spa-libs = {

src/daemon/pipewire.conf.in

@@ -26,6 +26,7 @@ context.properties = {
     #default.clock.quantum       = 1024
     #default.clock.min-quantum   = 32
     #default.clock.max-quantum   = 8192
+    #default.clock.quantum-limit = 8192
     #default.video.width         = 640
     #default.video.height        = 480
     #default.video.rate.num      = 25

src/modules/module-protocol-pulse/internal.h

@@ -52,6 +52,7 @@ struct defs {
 	struct sample_spec sample_spec;
 	struct channel_map channel_map;
 	uint32_t max_quantum;
+	uint32_t quantum_limit;
 };
 
 struct stats {

src/pipewire/context.c

@@ -980,26 +980,32 @@ static int collect_nodes(struct pw_context *context, struct pw_impl_node *driver
 }
 
 static inline void get_quantums(struct pw_context *context, uint32_t *def,
-		uint32_t *min, uint32_t *max, uint32_t *rate)
+		uint32_t *min, uint32_t *max, uint32_t *limit, uint32_t *rate)
 {
 	struct settings *s = &context->settings;
-	*def = s->clock_force_quantum == 0 ? s->clock_quantum : s->clock_force_quantum;
+	if (s->clock_force_quantum != 0) {
-	*min = s->clock_force_quantum == 0 ? s->clock_min_quantum : s->clock_force_quantum;
+		*def = *min = *max = s->clock_force_quantum;
-	*max = s->clock_force_quantum == 0 ? s->clock_max_quantum : s->clock_force_quantum;
+		*rate = 0;
-	*rate = s->clock_force_quantum == 0 ? s->clock_rate : s->clock_force_rate;
+	} else {
+		*def = s->clock_quantum;
+		*min = s->clock_min_quantum;
+		*max = s->clock_max_quantum;
+		*rate = s->clock_rate;
+	}
+	*limit = s->clock_quantum_limit;
 }
 
 static inline uint32_t *get_rates(struct pw_context *context, uint32_t *def, uint32_t *n_rates,
-		bool *force_rate)
+		bool *force)
 {
 	struct settings *s = &context->settings;
 	if (s->clock_force_rate != 0) {
-		*force_rate = true;
+		*force = true;
 		*n_rates = 1;
 		*def = s->clock_force_rate;
 		return &s->clock_force_rate;
 	} else {
-		*force_rate = false;
+		*force = false;
 		*n_rates = s->n_clock_rates;
 		*def = s->clock_rate;
 		return s->clock_rates;
@@ -1053,7 +1059,7 @@ int pw_context_recalc_graph(struct pw_context *context, const char *reason)
 {
 	struct impl *impl = SPA_CONTAINER_OF(context, struct impl, this);
 	struct pw_impl_node *n, *s, *target, *fallback;
-	uint32_t max_quantum, min_quantum, def_quantum, rate_quantum;
+	uint32_t max_quantum, min_quantum, def_quantum, lim_quantum, rate_quantum;
 	uint32_t *rates, n_rates, def_rate;
 	bool freewheel = false, force_rate;
 
@@ -1067,7 +1073,7 @@ int pw_context_recalc_graph(struct pw_context *context, const char *reason)
 again:
 	impl->recalc = true;
 
-	get_quantums(context, &def_quantum, &min_quantum, &max_quantum, &rate_quantum);
+	get_quantums(context, &def_quantum, &min_quantum, &max_quantum, &lim_quantum, &rate_quantum);
 	rates = get_rates(context, &def_rate, &n_rates, &force_rate);
 
 	/* start from all drivers and group all nodes that are linked
@@ -1221,6 +1227,7 @@ again:
 		if (rate_quantum != 0 && current_rate != rate_quantum) {
 			def_quantum = def_quantum * current_rate / rate_quantum;
 			min_quantum = min_quantum * current_rate / rate_quantum;
+			max_quantum = max_quantum * current_rate / rate_quantum;
 		}
 
 		/* calculate desired quantum */
@@ -1234,6 +1241,7 @@ again:
 		if (latency.denom != 0)
 			quantum = (latency.num * current_rate / latency.denom);
 		quantum = SPA_CLAMP(quantum, min_quantum, max_quantum);
+		quantum = SPA_MIN(quantum, lim_quantum);
 
 		if (context->settings.clock_power_of_two_quantum)
 			quantum = flp2(quantum);

src/pipewire/private.h

@@ -61,6 +61,7 @@ struct settings {
 	uint32_t clock_quantum;			/* default quantum */
 	uint32_t clock_min_quantum;		/* min quantum */
 	uint32_t clock_max_quantum;		/* max quantum */
+	uint32_t clock_quantum_limit;		/* quantum limit */
 	struct spa_rectangle video_size;
 	struct spa_fraction video_rate;
 	uint32_t link_max_buffers;

src/pipewire/settings.c

@@ -44,6 +44,7 @@
 #define DEFAULT_CLOCK_QUANTUM			1024u
 #define DEFAULT_CLOCK_MIN_QUANTUM		32u
 #define DEFAULT_CLOCK_MAX_QUANTUM		8192u
+#define DEFAULT_CLOCK_QUANTUM_LIMIT		8192u
 #define DEFAULT_CLOCK_POWER_OF_TWO_QUANTUM	true
 #define DEFAULT_VIDEO_WIDTH			640
 #define DEFAULT_VIDEO_HEIGHT			480
@@ -188,7 +189,7 @@ static int metadata_property(void *data, uint32_t subject, const char *key,
 		recalc = true;
 	} else if (spa_streq(key, "clock.force-quantum")) {
 		v = value ? atoi(value) : 0;
-		s->clock_force_quantum = SPA_MIN(v, 8192u);
+		s->clock_force_quantum = v;
 		recalc = true;
 	}
 	if (recalc)
@@ -213,6 +214,7 @@ void pw_settings_init(struct pw_context *this)
 	d->clock_quantum = get_default_int(p, "default.clock.quantum", DEFAULT_CLOCK_QUANTUM);
 	d->clock_min_quantum = get_default_int(p, "default.clock.min-quantum", DEFAULT_CLOCK_MIN_QUANTUM);
 	d->clock_max_quantum = get_default_int(p, "default.clock.max-quantum", DEFAULT_CLOCK_MAX_QUANTUM);
+	d->clock_quantum_limit = get_default_int(p, "default.clock.quantum-limit", DEFAULT_CLOCK_QUANTUM_LIMIT);
 	d->video_size.width = get_default_int(p, "default.video.width", DEFAULT_VIDEO_WIDTH);
 	d->video_size.height = get_default_int(p, "default.video.height", DEFAULT_VIDEO_HEIGHT);
 	d->video_rate.num = get_default_int(p, "default.video.rate.num", DEFAULT_VIDEO_RATE_NUM);
@@ -225,8 +227,10 @@ void pw_settings_init(struct pw_context *this)
 	d->mem_warn_mlock = get_default_bool(p, "mem.warn-mlock", DEFAULT_MEM_WARN_MLOCK);
 	d->mem_allow_mlock = get_default_bool(p, "mem.allow-mlock", DEFAULT_MEM_ALLOW_MLOCK);
 
-	d->clock_max_quantum = SPA_CLAMP(d->clock_max_quantum,
+	d->clock_quantum_limit = SPA_CLAMP(d->clock_quantum_limit,
 			CLOCK_MIN_QUANTUM, CLOCK_MAX_QUANTUM);
+	d->clock_max_quantum = SPA_CLAMP(d->clock_max_quantum,
+			CLOCK_MIN_QUANTUM, d->clock_quantum_limit);
 	d->clock_min_quantum = SPA_CLAMP(d->clock_min_quantum,
 			CLOCK_MIN_QUANTUM, d->clock_max_quantum);
 	d->clock_quantum = SPA_CLAMP(d->clock_quantum,