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@xxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_mtk.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index dd5e1cede2b58..c3f933d10295e 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; } -- 2.20.0.rc0.387.gc7a69e6b6c-goog