| Message ID | 20180321025241.19785-4-jk@ozlabs.org |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | serial: implement flow control for ASPEED VUART driver | expand |
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@linux.vnet.ibm.com> > > Signed-off-by: Jeremy Kerr <jk@ozlabs.org> > --- > 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);
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);
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 <jk@ozlabs.org> --- drivers/tty/serial/8250/8250_port.c | 3 ++- include/linux/serial_8250.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)