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| author |   Heiko Stübner <heiko@sntech.de> | 2013-12-05 00:54:38 +0100 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-08 17:16:05 -0800 |
| commit | 0da3336f19f2a42e9153efa4112d50fd148a8e61 (patch) | |
| tree | d9e7b69d4e15971b4efb51dfd06c32e7150a0743 /drivers/tty/serial/samsung.c | |
| parent | Linux 3.13-rc2 (diff) | |
| download | linux-dev-0da3336f19f2a42e9153efa4112d50fd148a8e61.tar.xz linux-dev-0da3336f19f2a42e9153efa4112d50fd148a8e61.zip | |
serial: samsung: move clock deactivation below uart registration
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>
Diffstat (limited to 'drivers/tty/serial/samsung.c')
| -rw-r--r-- | drivers/tty/serial/samsung.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index c1af04d46682..9cd706df3b33 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -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) |