Patch "ASoC: sgtl5000: Fix suspend/resume" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

ASoC: sgtl5000: Fix suspend/resume

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
asoc-sgtl5000-fix-suspend-resume.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Fabio Estevam <[email protected]>
Date: Fri, 16 Feb 2018 11:58:54 -0200
Subject: ASoC: sgtl5000: Fix suspend/resume

From: Fabio Estevam <[email protected]>

commit a8992973edbb2555e956b90f6fe97c4bc14d761d upstream.

Commit 8419caa72702 ("ASoC: sgtl5000: Do not disable regulators in SND_SOC_BIAS_OFF") causes the sgtl5000 to fail after a suspend/resume sequence:

Playing WAVE '/media/a2002011001-e02.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
aplay: pcm_write:2051: write error: Input/output error

The problem is caused by the fact that the aforementioned commit dropped the cache handling, so re-introduce the register map resync to fix the problem.

---
 sound/soc/codecs/sgtl5000.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

@@ -871,15 +871,26 @@ static int sgtl5000_pcm_hw_params(struct
 static int sgtl5000_set_bias_level(struct snd_soc_codec *codec,
 				   enum snd_soc_bias_level level)
 {
+	struct sgtl5000_priv *sgtl = snd_soc_codec_get_drvdata(codec);
+	int ret;
+
 	switch (level) {
 	case SND_SOC_BIAS_ON:
 	case SND_SOC_BIAS_PREPARE:
 	case SND_SOC_BIAS_STANDBY:
+		regcache_cache_only(sgtl->regmap, false);
+		ret = regcache_sync(sgtl->regmap);
+		if (ret) {
+			regcache_cache_only(sgtl->regmap, true);
+			return ret;
+		}
+
 		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
 				    SGTL5000_REFTOP_POWERUP,
 				    SGTL5000_REFTOP_POWERUP);
 		break;
 	case SND_SOC_BIAS_OFF:
+		regcache_cache_only(sgtl->regmap, true);
 		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
 				    SGTL5000_REFTOP_POWERUP, 0);
 		break;

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/asoc-sgtl5000-fix-suspend-resume.patch