diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c index dd19f17a1b63..2b8c479dbfa6 100644 --- a/drivers/mfd/twl6040.c +++ b/drivers/mfd/twl6040.c @@ -322,8 +322,19 @@ int twl6040_power(struct twl6040 *twl6040, int on) } } + /* + * Register access can produce errors after power-up unless we + * wait at least 8ms based on measurements on duovero. + */ + usleep_range(10000, 12000); + /* Sync with the HW */ - regcache_sync(twl6040->regmap); + ret = regcache_sync(twl6040->regmap); + if (ret) { + dev_err(twl6040->dev, "Failed to sync with the HW: %i\n", + ret); + goto out; + } /* Default PLL configuration after power up */ twl6040->pll = TWL6040_SYSCLK_SEL_LPPLL;