This is a note to let you know that I've just added the patch titled

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

to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 100bc3e2bebf95506da57cbdf5f26b25f6da4c81 Mon Sep 17 00:00:00 2001

From: Peter Shih pihsun@chromium.org Date: Tue, 27 Nov 2018 12:49:50 +0800 Subject: 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 --- 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 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; }