From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH V2] mfd: as3722: Handle interrupts on suspend Date: Tue, 24 Nov 2015 16:23:44 +0000 Message-ID: <20151124162344.GG807@x1> References: <1448016660-18819-1-git-send-email-jonathanh@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1448016660-18819-1-git-send-email-jonathanh@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Jon Hunter Cc: linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On Fri, 20 Nov 2015, Jon Hunter wrote: > The as3722 device is registered as an irqchip and the as3722-rtc inte= rrupt > is one of it's interrupt sources. When using the as3722-rtc as a wake= -up > device from suspend, the following is seen: >=20 > PM: Syncing filesystems ... done. > Freezing user space processes ... (elapsed 0.001 seconds) done. > Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done= =2E > Suspending console(s) (use no_console_suspend to debug) > PM: suspend of devices complete after 161.119 msecs > PM: late suspend of devices complete after 1.048 msecs > PM: noirq suspend of devices complete after 0.756 msecs > Disabling non-boot CPUs ... > CPU1: shutdown > CPU2: shutdown > CPU3: shutdown > Entering suspend state LP1 > Enabling non-boot CPUs ... > CPU1 is up > CPU2 is up > CPU3 is up > PM: noirq resume of devices complete after 0.487 msecs > as3722 4-0040: Failed to read IRQ status: -16 > as3722 4-0040: Failed to read IRQ status: -16 > as3722 4-0040: Failed to read IRQ status: -16 > as3722 4-0040: Failed to read IRQ status: -16 > ... >=20 > The reason why the as3722 interrupt status cannot be read is because = the > as3722 interrupt is not masked during suspend and when the as3722-rtc > interrupt occurs, to wake-up the device, the interrupt is seen before= the > i2c controller has been resumed in order to read the as3722 interrupt > status. >=20 > The as3722-rtc driver sets it's interrupt as a wake-up source during > suspend, which gets propagated to the parent as3722 interrupt. Howeve= r, > the as3722-rtc driver cannot disable it's interrupt during suspend > otherwise we would never be woken up and so the as3722 must disable i= t's > interrupt instead. >=20 > Fix this by disabling the as3722 interrupt during suspend. To ensure = that > a wake-up event from the as3722 is not missing, enable the as3722 int= errupt > as a wake-up source before disabling the interrupt on entering suspen= d. >=20 > Signed-off-by: Jon Hunter > --- >=20 > v2 changes: > - Re-enabled the interrupt in resume before disabling the wake-up. >=20 > drivers/mfd/as3722.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) Looks reasonable. Applied, thanks. > diff --git a/drivers/mfd/as3722.c b/drivers/mfd/as3722.c > index 924ea90494ae..3b21eb4bc480 100644 > --- a/drivers/mfd/as3722.c > +++ b/drivers/mfd/as3722.c > @@ -405,6 +405,8 @@ static int as3722_i2c_probe(struct i2c_client *i2= c, > goto scrub; > } > =20 > + device_init_wakeup(as3722->dev, true); > + > dev_dbg(as3722->dev, "AS3722 core driver initialized successfully\n= "); > return 0; > =20 > @@ -422,6 +424,29 @@ static int as3722_i2c_remove(struct i2c_client *= i2c) > return 0; > } > =20 > +static int as3722_i2c_suspend(struct device *dev) > +{ > + struct as3722 *as3722 =3D dev_get_drvdata(dev); > + > + if (device_may_wakeup(dev)) > + enable_irq_wake(as3722->chip_irq); > + disable_irq(as3722->chip_irq); > + > + return 0; > +} > + > +static int as3722_i2c_resume(struct device *dev) > +{ > + struct as3722 *as3722 =3D dev_get_drvdata(dev); > + > + enable_irq(as3722->chip_irq); > + > + if (device_may_wakeup(dev)) > + disable_irq_wake(as3722->chip_irq); > + > + return 0; > +} > + > static const struct of_device_id as3722_of_match[] =3D { > { .compatible =3D "ams,as3722", }, > {}, > @@ -434,10 +459,15 @@ static const struct i2c_device_id as3722_i2c_id= [] =3D { > }; > MODULE_DEVICE_TABLE(i2c, as3722_i2c_id); > =20 > +static const struct dev_pm_ops as3722_pm_ops =3D { > + SET_SYSTEM_SLEEP_PM_OPS(as3722_i2c_suspend, as3722_i2c_resume) > +}; > + > static struct i2c_driver as3722_i2c_driver =3D { > .driver =3D { > .name =3D "as3722", > .of_match_table =3D as3722_of_match, > + .pm =3D &as3722_pm_ops, > }, > .probe =3D as3722_i2c_probe, > .remove =3D as3722_i2c_remove, --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog