From a9fe8ba129810ef7912de732e1059eb9c6a5080b Mon Sep 17 00:00:00 2001 From: Mieczyslaw Nalewaj Date: Sun, 18 Jan 2026 15:24:46 +0100 Subject: [PATCH] serial: 8250: 6.18: add UPIO_AU case to set_io_from_upio() This patch fixes the "Unsupported UART type 4" error by adding support for the UPIO_AU I/O type in set_io_from_upio() (used by Au1x00 and RT288x). It assigns the correct serial input/output functions (io_serial_in, io_serial_out) for proper operation when UPIO_AU is configured. Signed-off-by: Mieczyslaw Nalewaj Link: https://github.com/openwrt/openwrt/pull/21078 Signed-off-by: Robert Marko --- ...add-UPIO_AU-case-to-set_io_from_upio.patch | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 target/linux/generic/hack-6.18/890-serial-8250-add-UPIO_AU-case-to-set_io_from_upio.patch diff --git a/target/linux/generic/hack-6.18/890-serial-8250-add-UPIO_AU-case-to-set_io_from_upio.patch b/target/linux/generic/hack-6.18/890-serial-8250-add-UPIO_AU-case-to-set_io_from_upio.patch new file mode 100644 index 0000000000..fd25bfca7e --- /dev/null +++ b/target/linux/generic/hack-6.18/890-serial-8250-add-UPIO_AU-case-to-set_io_from_upio.patch @@ -0,0 +1,25 @@ +From: Mieczyslaw Nalewaj +Date: Sun, 18 Jan 2026 15:24:46 +0100 +Subject: [PATCH] serial: 8250: add UPIO_AU case to set_io_from_upio() + +This patch fixes the "Unsupported UART type 4" error by adding support +for the UPIO_AU I/O type in set_io_from_upio() (used by Au1x00 and +RT288x). It assigns the correct serial input/output functions +(io_serial_in, io_serial_out) for proper operation when UPIO_AU is +configured. + +Signed-off-by: Mieczyslaw Nalewaj +--- + drivers/tty/serial/8250/8250_port.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/drivers/tty/serial/8250/8250_port.c ++++ b/drivers/tty/serial/8250/8250_port.c +@@ -454,6 +454,7 @@ static void set_io_from_upio(struct uart + break; + #ifdef CONFIG_HAS_IOPORT + case UPIO_PORT: ++ case UPIO_AU: + p->serial_in = io_serial_in; + p->serial_out = io_serial_out; + break;