[alsa-devel] [PATCH v2 2/3] ASoC: rt5645: Wait for 400msec before concluding on value of RT5645_VENDOR_ID2

[Alex Deucher]

From: Akshu Agrawal <akshu.agrawal at amd.com>

Minimum time required between power On of codec and read
of RT5645_VENDOR_ID2 is 400msec. We should wait that long
before reading the value.

TEST=Cold boot the device and check for sound device.

Signed-off-by: Akshu Agrawal <akshu.agrawal at amd.com>
Signed-off-by: Bard Liao <bardliao at realtek.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---

v2: rework the patch based on mailing list discussion.
    Just wait before reading the register.

 sound/soc/codecs/rt5645.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sound/soc/codecs/rt5645.c b/sound/soc/codecs/rt5645.c
index 23cc2cb8393f..ce5d2c3c6976 100644
--- a/sound/soc/codecs/rt5645.c
+++ b/sound/soc/codecs/rt5645.c
@@ -55,6 +55,8 @@ MODULE_PARM_DESC(quirk, "RT5645 pdata quirk override");
 
 #define RT5645_HWEQ_NUM 57
 
+#define TIME_TO_POWER_MS 400
+
 static const struct regmap_range_cfg rt5645_ranges[] = {
 	{
 		.name = "PR",
@@ -3786,6 +3788,13 @@ static int rt5645_i2c_probe(struct i2c_client *i2c,
 	}
 	regmap_read(regmap, RT5645_VENDOR_ID2, &val);
 
+	/*
+	 * Read after 400msec, as it is the interval required between
+	 * read and power On.
+	 */
+	msleep(TIME_TO_POWER_MS);
+	regmap_read(regmap, RT5645_VENDOR_ID2, &val);
+
 	switch (val) {
 	case RT5645_DEVICE_ID:
 		rt5645->regmap = devm_regmap_init_i2c(i2c, &rt5645_regmap);
-- 
2.13.6