tty: serial: 8250_mtk: always resume the device in probe.

serial8250_register_8250_port calls uart_config_port, which calls
config_port on the port before it tries to power on the port. So we need
the port to be on before calling serial8250_register_8250_port. Change
the code to always do a runtime resume in probe before registering port,
and always do a runtime suspend in remove.

This basically reverts the change in commit 68e5fc4a255a ("tty: serial:
8250_mtk: use pm_runtime callbacks for enabling"), but still use
pm_runtime callbacks.

Fixes: 68e5fc4a255a ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling")
Signed-off-by: Peter Shih <pihsun@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 9 deletions

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index dd5e1cede2b5..c3f933d10295 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -213,17 +213,17 @@ static int mtk8250_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, data);
 
-        pm_runtime_enable(&pdev->dev);
-        if (!pm_runtime_enabled(&pdev->dev)) {
-                err = mtk8250_runtime_resume(&pdev->dev);
-                if (err)
-                        return err;
-        }
+        err = mtk8250_runtime_resume(&pdev->dev);
+        if (err)
+                return err;
 
         data->line = serial8250_register_8250_port(&uart);
         if (data->line < 0)
                 return data->line;
 
+        pm_runtime_set_active(&pdev->dev);
+        pm_runtime_enable(&pdev->dev);
+
         return 0;
 }
 
@@ -234,13 +234,11 @@ static int mtk8250_remove(struct platform_device *pdev)
         pm_runtime_get_sync(&pdev->dev);
 
         serial8250_unregister_port(data->line);
+        mtk8250_runtime_suspend(&pdev->dev);
 
         pm_runtime_disable(&pdev->dev);
         pm_runtime_put_noidle(&pdev->dev);
 
-        if (!pm_runtime_status_suspended(&pdev->dev))
-                mtk8250_runtime_suspend(&pdev->dev);
-
         return 0;
 }