4.4-stable review patch. If anyone has any objections, please let me know.
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From: Peter Shih pihsun@chromium.org
commit 100bc3e2bebf95506da57cbdf5f26b25f6da4c81 upstream.
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(-)
--- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -231,17 +231,17 @@ static int mtk8250_probe(struct platform
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; }
@@ -252,13 +252,11 @@ static int mtk8250_remove(struct platfor 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; }