[alsa-devel] [PATCH 2/4] ASoC: SOF: PM: add check before setting d0_substate

[Pierre-Louis Bossart]

From: Keyon Jie <yang.jie at linux.intel.com>

Add check before seeting d0_substate and return success if Audio DSP is
already in the target substate.

Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 sound/soc/sof/pm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/sof/pm.c b/sound/soc/sof/pm.c
index 3204c92f0e7d..b89810bf3230 100644
--- a/sound/soc/sof/pm.c
+++ b/sound/soc/sof/pm.c
@@ -416,6 +416,9 @@ int snd_sof_set_d0_substate(struct snd_sof_dev *sdev,
 {
 	int ret;
 
+	if (sdev->d0_substate == d0_substate)
+		return 0;
+
 	/* do platform specific set_state */
 	ret = snd_sof_dsp_set_power_state(sdev, d0_substate);
 	if (ret < 0)
-- 
2.20.1