slimbus: stream: handle unsupported bitrates for presence rate

Handle errors of getting presence rate for unsupported stream bitrate,
instead of sending -EINVAL in change content message.
Signed-off-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: NKonrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118065246.6835-4-srinivas.kandagatla@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/slimbus/stream.c

@@ -204,7 +204,7 @@ int slim_stream_prepare(struct slim_stream_runtime *rt,
 {
 	struct slim_controller *ctrl = rt->dev->ctrl;
 	struct slim_port *port;
-	int num_ports, i, port_id;
+	int num_ports, i, port_id, prrate;
 
 	if (rt->ports) {
 		dev_err(&rt->dev->dev, "Stream already Prepared\n");
@@ -221,6 +221,13 @@ int slim_stream_prepare(struct slim_stream_runtime *rt,
 	rt->bps = cfg->bps;
 	rt->direction = cfg->direction;
 
+	prrate = slim_get_prate_code(cfg->rate);
+	if (prrate < 0) {
+		dev_err(&rt->dev->dev, "Cannot get presence rate for rate %d Hz\n",
+			cfg->rate);
+		return prrate;
+	}
+
 	if (cfg->rate % ctrl->a_framer->superfreq) {
 		/*
 		 * data rate not exactly multiple of super frame,
@@ -241,7 +248,7 @@ int slim_stream_prepare(struct slim_stream_runtime *rt,
 		port = &rt->ports[i];
 		port->state = SLIM_PORT_DISCONNECTED;
 		port->id = port_id;
-		port->ch.prrate = slim_get_prate_code(cfg->rate);
+		port->ch.prrate = prrate;
 		port->ch.id = cfg->chs[i];
 		port->ch.data_fmt = SLIM_CH_DATA_FMT_NOT_DEFINED;
 		port->ch.aux_fmt = SLIM_CH_AUX_FMT_NOT_APPLICABLE;