Messages in this thread Patch in this message | | | Date | Fri, 3 Oct 2014 15:45:37 +0800 | From | Joseph Lo <> | Subject | Re: [PATCH] serial: of-serial: add PM suspend/resume support |
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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 <jingchang.lu@freescale.com> > --- > 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, >
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