On Mon, Nov 15, 2021 at 10:42:01AM +0200, Tony Lindgren wrote:
> 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@xxxxxxxxxxx>
> ---
> 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);
Note that you still have synchronous resumes here despite this function
being called in atomic context. It didn't look like these were removed
by the next patch that drops irq_safe.
> @@ -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_noresume(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_noidle(port->dev);
> +
> pm_runtime_mark_last_busy(port->dev);
> pm_runtime_put_autosuspend(port->dev);
> free_irq(port->irq, port);
Johan
