[PATCH 5.18 228/231] serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle

Greg Kroah-Hartman
2022-07-19T13:12:11Z

From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

commit 211565b100993c90b53bf40851eacaefc830cfe0 upstream.

The driver must provide throttle and unthrottle in uart_ops when it
sets UPSTAT_AUTORTS. Add them using existing stop_rx &
enable_interrupts functions.

Fixes: 2a76fa283098 (serial: pl011: Adopt generic flag to store auto RTS status)
Cc: stable <stable@kernel.org>
Cc: Lukas Wunner <lukas@wunner.de>
Reported-by: Nuno Gonçalves <nunojpg@gmail.com>
Tested-by: Nuno Gonçalves <nunojpg@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220614075637.8558-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/amba-pl011.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)

--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1339,6 +1339,15 @@ static void pl011_stop_rx(struct uart_po
pl011_dma_rx_stop(uap);
}

+static void pl011_throttle_rx(struct uart_port *port)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ pl011_stop_rx(port);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
static void pl011_enable_ms(struct uart_port *port)
{
struct uart_amba_port *uap =
@@ -1760,9 +1769,10 @@ static int pl011_allocate_irq(struct uar
*/
static void pl011_enable_interrupts(struct uart_amba_port *uap)
{
+ unsigned long flags;
unsigned int i;

- spin_lock_irq(&uap->port.lock);
+ spin_lock_irqsave(&uap->port.lock, flags);

/* Clear out any spuriously appearing RX interrupts */
pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
@@ -1784,7 +1794,14 @@ static void pl011_enable_interrupts(stru
if (!pl011_dma_rx_running(uap))
uap->im |= UART011_RXIM;
pl011_write(uap->im, uap, REG_IMSC);
- spin_unlock_irq(&uap->port.lock);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+static void pl011_unthrottle_rx(struct uart_port *port)
+{
+ struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port);
+
+ pl011_enable_interrupts(uap);
}

static int pl011_startup(struct uart_port *port)
@@ -2211,6 +2228,8 @@ static const struct uart_ops amba_pl011_
.stop_tx = pl011_stop_tx,
.start_tx = pl011_start_tx,
.stop_rx = pl011_stop_rx,
+ .throttle = pl011_throttle_rx,
+ .unthrottle = pl011_unthrottle_rx,
.enable_ms = pl011_enable_ms,
.break_ctl = pl011_break_ctl,
.startup = pl011_startup,