[PATCH] ASoC: codecs: wcd938x: fix codec initialisation race

[Johan Hovold <johan+linaro@kernel.org>]

Make sure to resume the codec and soundwire device before trying to read
the codec variant and configure the device during component probe.

This specifically avoids interpreting (a masked and shifted) -EBUSY
errno as the variant:

	wcd938x_codec audio-codec: ASoC: error at soc_component_read_no_lock on audio-codec for register: [0x000034b0] -16

when the soundwire device happens to be suspended, which in turn
prevents some headphone controls from being registered.

Fixes: 8d78602aa87a ("ASoC: codecs: wcd938x: add basic driver")
Cc: stable@vger.kernel.org      # 5.14
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reported-by: Steev Klimaszewski <steev@kali.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 sound/soc/codecs/wcd938x.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/soc/codecs/wcd938x.c b/sound/soc/codecs/wcd938x.c
index e7d6a02cdec0..e3ae4fb2c4db 100644
--- a/sound/soc/codecs/wcd938x.c
+++ b/sound/soc/codecs/wcd938x.c
@@ -3085,6 +3085,10 @@ static int wcd938x_soc_codec_probe(struct snd_soc_component *component)
 
 	snd_soc_component_init_regmap(component, wcd938x->regmap);
 
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret < 0)
+		return ret;
+
 	wcd938x->variant = snd_soc_component_read_field(component,
 						 WCD938X_DIGITAL_EFUSE_REG_0,
 						 WCD938X_ID_MASK);
@@ -3098,6 +3102,8 @@ static int wcd938x_soc_codec_probe(struct snd_soc_component *component)
 			     (WCD938X_DIGITAL_INTR_LEVEL_0 + i), 0);
 	}
 
+	pm_runtime_put(dev);
+
 	wcd938x->hphr_pdm_wd_int = regmap_irq_get_virq(wcd938x->irq_chip,
 						       WCD938X_IRQ_HPHR_PDM_WD_INT);
 	wcd938x->hphl_pdm_wd_int = regmap_irq_get_virq(wcd938x->irq_chip,
-- 
2.39.3