Hi,
This patch might have a potential issue that cause system hard hung
immediately when it accesses to registers with no clock. This could
happen on many chips that mainline kernel supporting with the setting
"no_console_suspend=1" during suspend time.
On 09/23/2014 04:34 PM, Jingchang Lu wrote:
> This adds PM suspend/resume support for the of-serial driver
> to provide power management support on devices attatched to it.
>
> Signed-off-by: Jingchang Lu <[email protected]>
> ---
> drivers/tty/serial/of_serial.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
> index 27981e2..8bc2563 100644
> --- a/drivers/tty/serial/of_serial.c
> +++ b/drivers/tty/serial/of_serial.c
> @@ -240,6 +240,32 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
> return 0;
> }
>
> +#ifdef CONFIG_PM_SLEEP
> +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)
The fix would be something like this.
if (info->clk && console_suspend_enabled)
> + clk_disable_unprepare(info->clk);
> +
> + return 0;
> +}
> +
> +static int of_serial_resume(struct device *dev)
> +{
> + struct of_serial_info *info = dev_get_drvdata(dev);
> +
> + if (info->clk)
Ditto.
Thanks,
-Joseph
> + clk_prepare_enable(info->clk);
> +
> + serial8250_resume_port(info->line);
> +
> + return 0;
> +}
> +#endif
> +static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume);
> +
> /*
> * A few common types, add more as needed.
> */
> @@ -271,6 +297,7 @@ static struct platform_driver of_platform_serial_driver = {
> .name = "of_serial",
> .owner = THIS_MODULE,
> .of_match_table = of_platform_serial_table,
> + .pm = &of_serial_pm_ops,
> },
> .probe = of_platform_serial_probe,
> .remove = of_platform_serial_remove,
>
>-----Original Message-----
>From: Joseph Lo [mailto:[email protected]]
>Sent: Friday, October 03, 2014 3:46 PM
>To: Lu Jingchang-B35083; [email protected]
>Cc: [email protected]; [email protected]; linux-
>[email protected]; [email protected]; linux-arm-
>[email protected]
>Subject: Re: [PATCH] serial: of-serial: add PM suspend/resume support
>
>Hi,
>
>This patch might have a potential issue that cause system hard hung
>immediately when it accesses to registers with no clock. This could happen
>on many chips that mainline kernel supporting with the setting
>"no_console_suspend=1" during suspend time.
>
>On 09/23/2014 04:34 PM, Jingchang Lu wrote:
>> This adds PM suspend/resume support for the of-serial driver to
>> provide power management support on devices attatched to it.
>>
>> Signed-off-by: Jingchang Lu <[email protected]>
>> ---
>> drivers/tty/serial/of_serial.c | 27 +++++++++++++++++++++++++++
>> 1 file changed, 27 insertions(+)
>>
>> diff --git a/drivers/tty/serial/of_serial.c
>> b/drivers/tty/serial/of_serial.c index 27981e2..8bc2563 100644
>> --- a/drivers/tty/serial/of_serial.c
>> +++ b/drivers/tty/serial/of_serial.c
>> @@ -240,6 +240,32 @@ static int of_platform_serial_remove(struct
>platform_device *ofdev)
>> return 0;
>> }
>>
>> +#ifdef CONFIG_PM_SLEEP
>> +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)
>The fix would be something like this.
> if (info->clk && console_suspend_enabled)
>
Yes, there will be, I will send a fix on this, thanks!
Best Regards,
Jingchang
????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay? ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?