From: Claudiu Beznea <[email protected]>
In case the UART port is used as a console, no_console_suspend is
available in bootargs and UART port is part of a software-controlled power
domain we need to call device_set_awake_path(). This lets the power
domain core code know that this domain should not be powered off
during system suspend. Otherwise, the UART port power domain is turned off,
nothing is printed while suspending and the suspend/resume process is
blocked. This was detected on the Renesas RZ/G3S SoC while adding support
for power domains.
Based on code investigation (on v6.9-rc5), this issue is present on other
SoCs (e.g., Renesas R-Mobile A1 [1], IMX8QXP [2]) and different SoCs have
particular implementation to handle it. Due to this the patch added the
call of device_set_awake_path() in uart_suspend_port() instead of having
it in the platform specific UART driver.
[1] drivers/pmdomain/renesas/rmobile-sysc.c:116
[2] drivers/pmdomain/imx/scu-pd.c:357
Suggested-by: Ulf Hansson <[email protected]>
Suggested-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Tony Lindgren <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Claudiu Beznea <[email protected]>
---
Changes in v3:
- remove https links from commit description
- collected tags
- removed RFT tag
Changes in v2:
- used device_set_awake_path() instead of device_set_wakeup_path()
- moved the support in uart_suspend_port() to make it generic for
other drivers
- fixed typos in commit description
- updated the commit description to reflect the new changes and the fact
that support may be applied to other SoCs
- added Suggested-by tag; this was initially proposed by Ulf to move it
in the serial driver then Geert propose to have it more generic in
uart_suspend_port()
drivers/tty/serial/serial_core.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 8a76f378c445..84ae70d52b05 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2408,6 +2408,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
uport->ops->stop_rx(uport);
uart_port_unlock_irq(uport);
}
+ device_set_awake_path(uport->dev);
goto unlock;
}
--
2.39.2