On 03/20/2018 09:52 PM, Jeremy Kerr wrote:
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.
Tested-by: Eddie James <eajames@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx> --- 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 a5fe0e66c607..ea435406936c 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1650,7 +1650,7 @@ 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; @@ -1710,6 +1710,7 @@ 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 61fbb440449c..4639a3608614 100644 --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -162,6 +162,7 @@ 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);
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