From: Guanbing Huang <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. To address the issue of configuring the reg-shift property, the __uart_read_properties() universal interface is called to implement it. Adaptation of pnp devices is done in the __uart_read_properties() function. Guanbing Huang (3): pnp: Add dev_is_pnp() macro serial: 8250_port: Add support of pnp irq to __uart_read_properties() serial: 8250_pnp: Support configurable reg shift property drivers/tty/serial/8250/8250_pnp.c | 36 ++++++++++++++++++++---------- drivers/tty/serial/serial_port.c | 7 +++++- include/linux/pnp.h | 2 ++ 3 files changed, 32 insertions(+), 13 deletions(-) -- 2.17.1