[PATCH v4 3/5] ASoC: intel: atom: Use __free(kfree) for stream pointer

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

Declare 'stream' with __free(kfree) so it is automatically freed when
leaving scope. This allows direct returns from error paths and removes
the explicit kfree(stream) call.
Set 'stream' to NULL after ownership has been transferred to
runtime->private_data to prevent it from being freed on the success path.

This cleanup is a preparation step for upcoming locking changes.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---

Changes in v4:
 - Add cleanup.h include where needed.
 - update commit message

 sound/soc/intel/atom/sst-mfld-platform-pcm.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/sound/soc/intel/atom/sst-mfld-platform-pcm.c b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
index f074af2499c8..67506a718158 100644
--- a/sound/soc/intel/atom/sst-mfld-platform-pcm.c
+++ b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
@@ -11,6 +11,7 @@
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/cleanup.h>
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -304,7 +305,7 @@ static int sst_media_open(struct snd_pcm_substream *substream,
 {
 	int ret_val = 0;
 	struct snd_pcm_runtime *runtime = substream->runtime;
-	struct sst_runtime_stream *stream;
+	struct sst_runtime_stream *stream __free(kfree) = NULL;
 
 	stream = kzalloc_obj(*stream);
 	if (!stream)
@@ -330,7 +331,7 @@ static int sst_media_open(struct snd_pcm_substream *substream,
 
 	ret_val = power_up_sst(stream);
 	if (ret_val < 0)
-		goto out_power_up;
+		return ret_val;
 
 	/*
 	 * Make sure the period to be multiple of 1ms to align the
@@ -347,12 +348,19 @@ static int sst_media_open(struct snd_pcm_substream *substream,
 	snd_pcm_hw_constraint_step(substream->runtime, 0,
 			   SNDRV_PCM_HW_PARAM_PERIODS, 2);
 
-	return snd_pcm_hw_constraint_integer(runtime,
-			 SNDRV_PCM_HW_PARAM_PERIODS);
+	ret_val = snd_pcm_hw_constraint_integer(runtime,
+						SNDRV_PCM_HW_PARAM_PERIODS);
+
+	if (ret_val < 0)
+		return ret_val;
+
+	stream = NULL;
+
+	return ret_val;
+
 out_ops:
 	mutex_unlock(&sst_lock);
-out_power_up:
-	kfree(stream);
+
 	return ret_val;
 }
 
-- 
2.43.0