ASoC: nau8825: fix static check error about semaphone control

The patch is to fix the static check error as the following.

The patch commit b50455fab459 ("ASoC: nau8825: cross talk suppression
measurement function") from Jun 7, 2016, leads to the following
static checker warning:

	sound/soc/codecs/nau8825.c:265 nau8825_sema_acquire()
	warn: 'sem:&nau8825->xtalk_sem' is sometimes locked here and
	sometimes unlocked.

The semaphone acquire function has return value, and some callers
can do error handling when lock fails.

Signed-off-by: John Hsu <KCHSU0@nuvoton.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/nau8825.c b/sound/soc/codecs/nau8825.c
index 20d2f1578b8761bf768203a4316a59bf36bd7676..2e59a85e360b67cb89ffed8fca86148db8d0a6c1 100644 (file)
--- a/sound/soc/codecs/nau8825.c
+++ b/sound/soc/codecs/nau8825.c
@@ -225,19 +225,26 @@ static const unsigned short logtable[256] = {
  * Acquires the semaphore without jiffies. If no more tasks are allowed
  * to acquire the semaphore, calling this function will put the task to
  * sleep until the semaphore is released.
- * It returns if the semaphore was acquired.
+ * If the semaphore is not released within the specified number of jiffies,
+ * this function returns -ETIME.
+ * If the sleep is interrupted by a signal, this function will return -EINTR.
+ * It returns 0 if the semaphore was acquired successfully.
  */
-static void nau8825_sema_acquire(struct nau8825 *nau8825, long timeout)
+static int nau8825_sema_acquire(struct nau8825 *nau8825, long timeout)
 {
        int ret;
 
-       if (timeout)
+       if (timeout) {
                ret = down_timeout(&nau8825->xtalk_sem, timeout);
-       else
+               if (ret < 0)
+                       dev_warn(nau8825->dev, "Acquire semaphone timeout\n");
+       } else {
                ret = down_interruptible(&nau8825->xtalk_sem);
+               if (ret < 0)
+                       dev_warn(nau8825->dev, "Acquire semaphone fail\n");
+       }
 
-       if (ret < 0)
-               dev_warn(nau8825->dev, "Acquire semaphone fail\n");
+       return ret;
 }
 
 /**
@@ -1596,8 +1603,11 @@ static irqreturn_t nau8825_interrupt(int irq, void *data)
                                         * cess and restore changes if process
                                         * is ongoing when ejection.
                                         */
+                                       int ret;
                                        nau8825->xtalk_protect = true;
-                                       nau8825_sema_acquire(nau8825, 0);
+                                       ret = nau8825_sema_acquire(nau8825, 0);
+                                       if (ret < 0)
+                                               nau8825->xtalk_protect = false;
                                }
                                /* Startup cross talk detection process */
                                nau8825->xtalk_state = NAU8825_XTALK_PREPARE;
@@ -2223,11 +2233,14 @@ static int __maybe_unused nau8825_suspend(struct snd_soc_codec *codec)
 static int __maybe_unused nau8825_resume(struct snd_soc_codec *codec)
 {
        struct nau8825 *nau8825 = snd_soc_codec_get_drvdata(codec);
+       int ret;
 
        regcache_cache_only(nau8825->regmap, false);
        regcache_sync(nau8825->regmap);
        nau8825->xtalk_protect = true;
-       nau8825_sema_acquire(nau8825, 0);
+       ret = nau8825_sema_acquire(nau8825, 0);
+       if (ret < 0)
+               nau8825->xtalk_protect = false;
        enable_irq(nau8825->irq);
 
        return 0;