[alsa-devel] [PATCH 1/2] ASoC: wm_adsp: Return an error on write to a disabled volatile control

[Charles Keepax]

Volatile controls should only be accessed when the firmware is active,
currently however writes to these controls will succeed, but the data
will be lost, if the firmware is powered down. Update this behaviour such
that an error is returned the same as it is for reads.

Signed-off-by: Charles Keepax <ckeepax at opensource.wolfsonmicro.com>
---
 sound/soc/codecs/wm_adsp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index d151224..6313b3d 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -899,7 +899,10 @@ static int wm_coeff_put(struct snd_kcontrol *kctl,
 
 	mutex_lock(&ctl->dsp->pwr_lock);
 
-	memcpy(ctl->cache, p, ctl->len);
+	if (ctl->flags & WMFW_CTL_FLAG_VOLATILE)
+		ret = -EPERM;
+	else
+		memcpy(ctl->cache, p, ctl->len);
 
 	ctl->set = 1;
 	if (ctl->enabled && ctl->dsp->running)
@@ -926,6 +929,8 @@ static int wm_coeff_tlv_put(struct snd_kcontrol *kctl,
 		ctl->set = 1;
 		if (ctl->enabled && ctl->dsp->running)
 			ret = wm_coeff_write_control(ctl, ctl->cache, size);
+		else if (ctl->flags & WMFW_CTL_FLAG_VOLATILE)
+			ret = -EPERM;
 	}
 
 	mutex_unlock(&ctl->dsp->pwr_lock);
-- 
2.1.4