From: Akshu Agrawal <akshu.agrawal@xxxxxxx> 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