[PATCH 3/4] serial: 8250_omap: Require a valid wakeirq for deeper idle states

Tony Lindgren
2021-10-15T11:26:51Z

For deeper idle states the 8250 device gets powered off. The wakeup is
handled with a separate wakeirq controller monitoring the RX pin.

Let's check for a valid wakeirq before enabling deeper idle states.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
drivers/tty/serial/8250/8250_omap.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -133,6 +133,7 @@ struct omap8250_priv {
spinlock_t rx_dma_lock;
bool rx_dma_broken;
bool throttled;
+ unsigned int allow_rpm:1;
};

struct omap8250_dma_params {
@@ -676,6 +677,7 @@ static int omap_8250_startup(struct uart_port *port)
ret = dev_pm_set_dedicated_wake_irq(port->dev, priv->wakeirq);
if (ret)
return ret;
+ priv->allow_rpm = 1;
}

pm_runtime_get_sync(port->dev);
@@ -722,6 +724,10 @@ static int omap_8250_startup(struct uart_port *port)
if (up->dma && !(priv->habit & UART_HAS_EFR2))
up->dma->rx_dma(up);

+ /* Block runtime PM if no wakeirq, paired with shutdown */
+ if (!priv->allow_rpm)
+ pm_runtime_get(port->dev);
+
pm_runtime_mark_last_busy(port->dev);
pm_runtime_put_autosuspend(port->dev);
return 0;
@@ -760,6 +766,10 @@ static void omap_8250_shutdown(struct uart_port *port)
serial_out(up, UART_LCR, up->lcr & ~UART_LCR_SBC);
serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);

+ /* Clear possible PM runtime block to pair with startup */
+ if (!priv->allow_rpm)
+ pm_runtime_put(port->dev);
+
pm_runtime_mark_last_busy(port->dev);
pm_runtime_put_autosuspend(port->dev);
free_irq(port->irq, port);
--
2.33.0