Commit 55484fcc authored May 19, 2020 by Erwan Le Ray Committed by Greg Kroah-Hartman May 19, 2020

serial: stm32: add no_console_suspend support

In order to display console messages in low power mode, console pins
must be kept active after suspend call.

Initial patch "serial: stm32: add support for no_console_suspend" was part
of "STM32 usart power improvement" series, but as dependancy to
console_suspend pinctl state has been removed to fit with Rob comment [1],
this patch has no more dependancy with any other patch of this series.

[1] https://lkml.org/lkml/2019/7/9/451



Signed-off-by: Erwan Le Ray <erwan.leray@st.com>

Link: https://lore.kernel.org/r/20200519094104.27082-1-erwan.leray@st.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b14109f3

drivers/tty/serial/stm32-usart.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -1424,7 +1424,18 @@ static int __maybe_unused stm32_serial_suspend(struct device *dev)
		else
		stm32_serial_enable_wakeup(port, false);

		/*
		* When "no_console_suspend" is enabled, keep the pinctrl default state
		* and rely on bootloader stage to restore this state upon resume.
		* Otherwise, apply the idle or sleep states depending on wakeup
		* capabilities.
		*/
		if (console_suspend_enabled \|\| !uart_console(port)) {
		if (device_may_wakeup(dev))
		pinctrl_pm_select_idle_state(dev);
		else
		pinctrl_pm_select_sleep_state(dev);
		}

		return 0;
		}

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