From: albanhuang <albanhuang@xxxxxxxxxxx> The 16550a serial port based on the ACPI table requires obtaining the reg-shift attribute. In the ACPI scenario, If the reg-shift property is not configured like in DTS, the 16550a serial driver cannot read or write controller registers properly during initialization. Signed-off-by: albanhuang <albanhuang@xxxxxxxxxxx> Signed-off-by: tombinfan <tombinfan@xxxxxxxxxxx> Signed-off-by: dylanlhdu <dylanlhdu@xxxxxxxxxxx> --- drivers/tty/serial/8250/8250_pnp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c index 1974bbadc975..25b4e41e9745 100644 --- a/drivers/tty/serial/8250/8250_pnp.c +++ b/drivers/tty/serial/8250/8250_pnp.c @@ -473,6 +473,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id) uart.port.flags |= UPF_SHARE_IRQ; uart.port.uartclk = 1843200; device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk); + device_property_read_u8(&dev->dev, "reg-shift", &uart.port.regshift); uart.port.dev = &dev->dev; line = serial8250_register_8250_port(&uart); -- 2.17.1
