soundwire: return earlier if no slave is attached

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@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210126085439.4349-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 82df088c9333897e77c3ee9b58583a797afff772..d9deafdcf495efb6a07b65e2bf248d7d592a7744 100644 (file)
--- 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)
-               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
-        */
+       /* 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);
+
        list_for_each_entry(slave, &bus->slaves, node) {
                if (!slave->dev_num)
                        continue;