serial: 8250_omap: Use force_suspend and resume for system suspend

[ Upstream commit 20a41a62618df85f3a2981008edec5cadd785e0a ]

We should not rely on autosuspend timeout for system suspend. Instead,
let's use force_suspend and force_resume functions. Otherwise the serial
port controller device may not be idled on suspend.

As we are doing a register write on suspend to configure the serial port,
we still need to runtime PM resume the port on suspend.

While at it, let's switch to pm_runtime_resume_and_get() and check for
errors returned. And let's add the missing line break before return to the
suspend function while at it.

Fixes: 09d8b2bdbc5c ("serial: 8250: omap: Provide ability to enable/disable UART as wakeup source")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Dhruva Gole <d-gole@ti.com>
Message-ID: <20230614045922.4798-1-tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 17a2302..adc85e2 100644 (file)
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1505,25 +1505,35 @@ static int omap8250_suspend(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
        struct uart_8250_port *up = serial8250_get_port(priv->line);
+       int err;
 
        serial8250_suspend_port(priv->line);
 
-       pm_runtime_get_sync(dev);
+       err = pm_runtime_resume_and_get(dev);
+       if (err)
+               return err;
        if (!device_may_wakeup(dev))
                priv->wer = 0;
        serial_out(up, UART_OMAP_WER, priv->wer);
-       pm_runtime_mark_last_busy(dev);
-       pm_runtime_put_autosuspend(dev);
-
+       err = pm_runtime_force_suspend(dev);
        flush_work(&priv->qos_work);
-       return 0;
+
+       return err;
 }
 
 static int omap8250_resume(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
+       int err;
 
+       err = pm_runtime_force_resume(dev);
+       if (err)
+               return err;
        serial8250_resume_port(priv->line);
+       /* Paired with pm_runtime_resume_and_get() in omap8250_suspend() */
+       pm_runtime_mark_last_busy(dev);
+       pm_runtime_put_autosuspend(dev);
+
        return 0;
 }
 #else