Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Wed, 21 Sep 2022 20:13:29 +0200 | Subject | Re: [RFC] PM: core: Add pm_wakeup_pending check in device suspend_noirq |
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On Fri, Sep 16, 2022 at 4:15 AM cy_huang <u0084500@gmail.com> wrote: > > From: ChiYuan Huang <cy_huang@richtek.com> > > In 'dpm_suspend_noirq', it will do the sychronized_irq to guarantee all > irqs are all done, and then do any wakeup flag set. > > For some peripherial deivces like as I2C/SPI, to speed up the irq handling, > it may use 'pm_stay_awake' and really handle in another thread context like > as workqueue. > > But in mem suspend flow, after 'dpm_suspend_noirq" stage, the next > 'pm_wakeup_pending' check will be at 'syscore_suspend'. > > The checkpoint seems too late and cause I2C/SPI fail during 'noirq' to > 'syscore_suspend'
What exactly do you mean by "fail" here?
>. But some adapter was already be marked as 'suspended' > at 'noirq' callback, any I2C/SPI xfer will return the error flag '-ESHUTDOWN'. > > After the code trace, it seems all device callback will do 'pm_wakeup_pending' > check, except 'noirq'. > > This patch is to add 'pm_wakeup_pending' check in 'noirq' sage to prevent this > kind of usage. > > Signed-off-by: ChiYuan Huang <cy_huang@richtek.com> > --- > Hi, > > Is there any rule to define when I2C/SPI host controller need to mark adapter as > 'suspended'? > > I trace 'drivers/i2c/buses'.It seems there's no common rule, Some are 'suspend', > others may did it at 'suspend_noirq'. > > --- > drivers/base/power/main.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index c501392..7cd7dc5 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -1210,6 +1210,11 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a > if (async_error) > goto Complete; > > + if (pm_wakeup_pending()) { > + async_error = -EBUSY; > + goto Complete; > + } > + > if (dev->power.syscore || dev->power.direct_complete) > goto Complete; > > -- > 2.7.4 >
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