From ebbaf9ab9ebd69f42b286c7a67cc84571c3d947a Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Tue, 27 Mar 2018 11:48:25 +0800 Subject: [PATCH] serial/8250: export serial8250_read_char Currently, we export serial8250_rx_chars, which does a whole bunch of reads from the 8250 data register, without any form of flow control between reads. An upcoming change to the aspeed vuart driver implements more fine-grained flow control in the interrupt handler, requiring character-at-a-time control over the rx path. This change exports serial8250_read_char to allow this. Signed-off-by: Jeremy Kerr Tested-by: Eddie James Tested-by: Joel Stanley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 3 ++- include/linux/serial_8250.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 95833cbc4338..8fbd5fbeb318 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1680,7 +1680,7 @@ static void serial8250_enable_ms(struct uart_port *port) serial8250_rpm_put(up); } -static void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) +void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) { struct uart_port *port = &up->port; unsigned char ch; @@ -1740,6 +1740,7 @@ static void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) uart_insert_char(port, lsr, UART_LSR_OE, ch, flag); } +EXPORT_SYMBOL_GPL(serial8250_read_char); /* * serial8250_rx_chars: processes according to the passed in LSR diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h index a27ef5f56431..76b9db71e489 100644 --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -163,6 +163,7 @@ extern void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl); extern int fsl8250_handle_irq(struct uart_port *port); int serial8250_handle_irq(struct uart_port *port, unsigned int iir); unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr); +void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr); void serial8250_tx_chars(struct uart_8250_port *up); unsigned int serial8250_modem_status(struct uart_8250_port *up); void serial8250_init_port(struct uart_8250_port *up); -- 2.45.2