Hi Jingchang,
On 10/09/2014 05:10 AM, Jingchang Lu wrote:
> Mandatorily disabling the uart clock will cause register access
> hung on "no_console_suspend". This patch add condition check on
> it and only disable the clock with console_suspend_enabled true.
>
> Signed-off-by: Joseph Lo <josephl@xxxxxxxxxx>
> Signed-off-by: Jingchang Lu <jingchang.lu@xxxxxxxxxxxxx>
> ---
> drivers/tty/serial/of_serial.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
> index 8bc2563..a765399 100644
> --- a/drivers/tty/serial/of_serial.c
> +++ b/drivers/tty/serial/of_serial.c
> @@ -246,7 +246,7 @@ static int of_serial_suspend(struct device *dev)
> struct of_serial_info *info = dev_get_drvdata(dev);
>
> serial8250_suspend_port(info->line);
> - if (info->clk)
> + if (info->clk && console_suspend_enabled)
> clk_disable_unprepare(info->clk);
This needs to check that _this_ port is the console port, like:
if (info->clk && uart_console(port) && and console_suspend_enabled)
clk_disable_unprepare(info->clk);
which means you need something like:
struct uart_8250_port *uart = serial8250_get_port(info->line);
struct uart_port *port = &uart->port;
Also, there's another problem with your original patch:
not every of_serial device is an 8250, right?
serial8250_suspend_port() on a port that's not registered with 8250 core
is probably going to blow up.
Which means the body of of_platform_suspend() and of_platform_resume()
should probably look like
switch (info->type) {
#ifdef CONFIG_SERIAL_8250
case PORT_8250 ... PORT_MAX_8250:
{
/* current body of function */
}
#endif
default:
}
Regards,
Peter Hurley
>
> return 0;
> @@ -256,7 +256,7 @@ static int of_serial_resume(struct device *dev)
> {
> struct of_serial_info *info = dev_get_drvdata(dev);
>
> - if (info->clk)
> + if (info->clk && console_suspend_enabled)
> clk_prepare_enable(info->clk);
>
> serial8250_resume_port(info->line);
>
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