Messages in this thread | | | Date | Thu, 26 Jun 2014 18:18:43 +0200 | From | Javier Martinez Canillas <> | Subject | Re: [PATCH v4 07/14] mfd: Add driver for Maxim 77802 Power Management IC |
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Hello Doug,
On 06/26/2014 06:12 PM, Doug Anderson wrote: > Javier, > > On Thu, Jun 26, 2014 at 4:13 AM, Javier Martinez Canillas > <javier.martinez@collabora.co.uk> wrote: >>>> + >>>> +#ifdef CONFIG_PM_SLEEP >>>> +static int max77802_suspend(struct device *dev) >>>> +{ >>>> + struct i2c_client *i2c = container_of(dev, struct i2c_client, dev); >>>> + struct max77802_dev *max77802 = i2c_get_clientdata(i2c); >>>> + >>>> + if (device_may_wakeup(dev)) >>>> + enable_irq_wake(max77802->irq); >>>> + >>>> + disable_irq(max77802->irq); >>> >>> Can you add short comment why this is needed? I know why but just for >>> future generations which will wonder: "why do we need to disable the IRQ >>> while suspending?" :). Especially that this is rather a workaround for >>> issue in other driver (I2C bus). >>> >> >> Good idea, I'll add a comment here on next version so code archaeologists can >> figure out what what's going on here. > > Is the disable_irq() needed if you have > <https://patchwork.kernel.org/patch/4421891/>? >
Probably not but I added the following comment:
/* * The IRQ must be disabled during suspend since due wakeup * ordering issues it may be possible that the I2C controller * is still suspended when the interrupt happens so the IRQ * handler will fail to read the I2C bus. */ disable_irq(max77802->irq);
since in theory this PMIC can be used in other SoCs besides Exynos5420/Exynos5800 and it may be possible that the I2C controller driver for these other SoCs may not resume at noirq time.
But on a second thought, this PMIC seems to be designed specially for these two Exynos SoCs so I guess it's safe to assume that it is not needed?
Best regards, Javier
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