2014-10-27 2:24 GMT-07:00 Jingchang Lu <jingchang.lu@xxxxxxxxxxxxx>:
> This patch fixes commit 2dea53bf57783f243c892e99c10c6921e956aa7e,
> "serial: of-serial: add PM suspend/resume support", which disables
> the uart clock on suspend, but also causes a hardware hang on register
> access if no_console_suspend command line option is used.
>
> Also, not every of_serial device is an 8250 port, so the serial8250
> suspend/resume functions should only be applied to a real 8250 port.
Greg, can you pick this one and submit it for your next 3.18-rc
submission? This fixes a regression when using "no_console_suspend"
introduced by:
2dea53bf57783f243c892e99c10c6921e956aa7e ("serial: of-serial: add PM
suspend/resume support") which has been merged during 3.18-rc1
Thanks!
>
> Reported-By: Joseph Lo <josephl@xxxxxxxxxx>
> Signed-off-by: Jingchang Lu <jingchang.lu@xxxxxxxxxxxxx>
> Tested-By: Joseph Lo <josephl@xxxxxxxxxx>
> Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
> ---
> changes in v5:
> add missing <linux/console.h> include.
>
> changes in v4:
> separate 8250 port suspend/resume from of_serial_suspend/resume.
>
> changes in v3:
> fix up point reference and deference.
>
> changes in v2:
> add switch selection on uart type.
>
> drivers/tty/serial/of_serial.c | 53 ++++++++++++++++++++++++++++++++++++------
> 1 file changed, 46 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
> index 8bc2563..9c64ad2 100644
> --- a/drivers/tty/serial/of_serial.c
> +++ b/drivers/tty/serial/of_serial.c
> @@ -9,6 +9,7 @@
> * 2 of the License, or (at your option) any later version.
> *
> */
> +#include <linux/console.h>
> #include <linux/module.h>
> #include <linux/slab.h>
> #include <linux/delay.h>
> @@ -241,13 +242,48 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
> }
>
> #ifdef CONFIG_PM_SLEEP
> -static int of_serial_suspend(struct device *dev)
> +#ifdef CONFIG_SERIAL_8250
> +static void of_serial_suspend_8250(struct of_serial_info *info)
> {
> - struct of_serial_info *info = dev_get_drvdata(dev);
> + struct uart_8250_port *port8250 = serial8250_get_port(info->line);
> + struct uart_port *port = &port8250->port;
>
> serial8250_suspend_port(info->line);
> - if (info->clk)
> + if (info->clk && (!uart_console(port) || console_suspend_enabled))
> clk_disable_unprepare(info->clk);
> +}
> +
> +static void of_serial_resume_8250(struct of_serial_info *info)
> +{
> + struct uart_8250_port *port8250 = serial8250_get_port(info->line);
> + struct uart_port *port = &port8250->port;
> +
> + if (info->clk && (!uart_console(port) || console_suspend_enabled))
> + clk_prepare_enable(info->clk);
> +
> + serial8250_resume_port(info->line);
> +}
> +#else
> +static inline void of_serial_suspend_8250(struct of_serial_info *info)
> +{
> +}
> +
> +static inline void of_serial_resume_8250(struct of_serial_info *info)
> +{
> +}
> +#endif
> +
> +static int of_serial_suspend(struct device *dev)
> +{
> + struct of_serial_info *info = dev_get_drvdata(dev);
> +
> + switch(info->type) {
> + case PORT_8250 ... PORT_MAX_8250:
> + of_serial_suspend_8250(info);
> + break;
> + default:
> + break;
> + }
>
> return 0;
> }
> @@ -256,10 +292,13 @@ static int of_serial_resume(struct device *dev)
> {
> struct of_serial_info *info = dev_get_drvdata(dev);
>
> - if (info->clk)
> - clk_prepare_enable(info->clk);
> -
> - serial8250_resume_port(info->line);
> + switch(info->type) {
> + case PORT_8250 ... PORT_MAX_8250:
> + of_serial_resume_8250(info);
> + break;
> + default:
> + break;
> + }
>
> return 0;
> }
> --
> 1.8.0
>
>
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--
Florian
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