[PATCH] soundwire: return earlier if no slave is attached

[Bard Liao]

From: Chao Song <chao.song@xxxxxxxxxxxxxxx>

If there is no slave attached to soundwire bus, we
can return earlier from sdw_bus_prep_clk_stop() and
sdw_bus_exit_clk_stop(), this saves a redundant value
check.

Signed-off-by: Chao Song <chao.song@xxxxxxxxxxxxxxx>
Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
 drivers/soundwire/bus.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 82df088c9333..d9deafdcf495 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -951,17 +951,17 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
 			simple_clk_stop = false;
 	}
 
-	if (is_slave && !simple_clk_stop) {
+	/* Skip remaining clock stop preparation if no Slave is attached */
+	if (!is_slave)
+		return ret;
+
+	if (!simple_clk_stop) {
 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
 						       SDW_BROADCAST_DEV_NUM);
 		if (ret < 0)
 			return ret;
 	}
 
-	/* Don't need to inform slaves if there is no slave attached */
-	if (!is_slave)
-		return ret;
-
 	/* Inform slaves that prep is done */
 	list_for_each_entry(slave, &bus->slaves, node) {
 		if (!slave->dev_num)
@@ -1075,16 +1075,13 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
 				 "clk stop deprep failed:%d", ret);
 	}
 
-	if (is_slave && !simple_clk_stop)
+	/* Skip remaining clock stop de-preparation if no Slave is attached */
+	if (!is_slave)
+		return 0;
+
+	if (!simple_clk_stop)
 		sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
 
-	/*
-	 * Don't need to call slave callback function if there is no slave
-	 * attached
-	 */
-	if (!is_slave)
-		return 0;
-
 	list_for_each_entry(slave, &bus->slaves, node) {
 		if (!slave->dev_num)
 			continue;
-- 
2.17.1