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serial: samsung: move clock deactivation below uart registration

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Commit 60e93575476f (serial: samsung: enable clock before clearing pending
interrupts during init) added handling of the controller clock during init.

On most systems this clock is also one of the baud_clock sources and
possibly used by the earlycon and thus already enabled by the bootloader.

Therefore a gap exists between s3c24xx_serial_init_port disabling the
clock and an attached console reenabling it, making the transition from
earlycon to regular console possibly hang the system - as seen on my
S3C2442 based Freerunner today.

Therefore move the disabling of the clock from s3c24xx_serial_init_port
below the uart port registration, effectively creating an overlap and
keeping the clock running non-stop if the console wants to grab this port.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Heiko Stübner 2013-12-05 00:54:38 +01:00 committed by Greg Kroah-Hartman
parent dc1ccc4815
commit 0da3336f19
1 changed files with 7 additions and 1 deletions
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8
drivers/tty/serial/samsung.c
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@ -1209,7 +1209,6 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
/* reset the fifos (and setup the uart) */
s3c24xx_serial_resetport(port, cfg);
clk_disable_unprepare(ourport->clk);
return 0;
}
@ -1287,6 +1286,13 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
platform_set_drvdata(pdev, &ourport->port);
/*
* Deactivate the clock enabled in s3c24xx_serial_init_port here,
* so that a potential re-enablement through the pm-callback overlaps
* and keeps the clock enabled in this case.
*/
clk_disable_unprepare(ourport->clk);
#ifdef CONFIG_SAMSUNG_CLOCK
ret = device_create_file(&pdev->dev, &dev_attr_clock_source);
if (ret < 0)