serial: rda: drop low-latency workaround

The rda driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
been removed years before the driver was added by commit c10b13325ced
("tty: serial: Add RDA8810PL UART driver").

Specifically, since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-19-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c
index 85366e0..d550d8f 100644 (file)
--- a/drivers/tty/serial/rda-uart.c
+++ b/drivers/tty/serial/rda-uart.c
@@ -398,9 +398,7 @@ static void rda_uart_receive_chars(struct uart_port *port)
                status = rda_uart_read(port, RDA_UART_STATUS);
        }
 
-       spin_unlock(&port->lock);
        tty_flip_buffer_push(&port->state->port);
-       spin_lock(&port->lock);
 }
 
 static irqreturn_t rda_interrupt(int irq, void *dev_id)