According to the IOControl register bits description in the page 31 of the product datasheet, we know the bit 3 of IOControl register is softreset, this bit will self-clearing once the reset finish. In the probe, the softreset bit is set, and when we read this register from debugfs/regmap interface, we found the softreset bit is still setting, this confused us for a while. Finally we found this register is cached, to read the real value from register, we could put it into the regmap_volatile(). Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx> --- drivers/tty/serial/sc16is7xx.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 2e7e7c409cf2..bc2b204d63af 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -488,6 +488,7 @@ static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) case SC16IS7XX_TXLVL_REG: case SC16IS7XX_RXLVL_REG: case SC16IS7XX_IOSTATE_REG: + case SC16IS7XX_IOCONTROL_REG: return true; default: break; -- 2.34.1
