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    SubjectRe: [PATCH v1 3/3] i2c: tegra: Fix suspending in active runtime PM state
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    Date
    13.12.2019 02:34, Dmitry Osipenko пишет:
    > I noticed that sometime I2C clock is kept enabled during suspend-resume.
    > This happens because runtime PM defers dynamic suspension and thus it may
    > happen that runtime PM is in active state when system enters into suspend.
    > In particular I2C controller that is used for CPU's DVFS is often kept ON
    > during suspend because CPU's voltage scaling happens quite often.
    >
    > Note: we marked runtime PM as IRQ-safe during the driver's probe in the
    > "Support atomic transfers" patch, thus it's okay to enforce runtime PM
    > suspend/resume in the NOIRQ phase which is used for the system-level
    > suspend/resume of the driver.
    >
    > Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
    > ---
    > drivers/i2c/busses/i2c-tegra.c | 9 +++++++++
    > 1 file changed, 9 insertions(+)
    >
    > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
    > index b3ecdd87e91f..d309a314f4d6 100644
    > --- a/drivers/i2c/busses/i2c-tegra.c
    > +++ b/drivers/i2c/busses/i2c-tegra.c
    > @@ -1790,9 +1790,14 @@ static int tegra_i2c_remove(struct platform_device *pdev)
    > static int __maybe_unused tegra_i2c_suspend(struct device *dev)
    > {
    > struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
    > + int err;
    >
    > i2c_mark_adapter_suspended(&i2c_dev->adapter);
    >
    > + err = pm_runtime_force_suspend(dev);
    > + if (err < 0)
    > + return err;
    > +
    > return 0;
    > }
    >
    > @@ -1813,6 +1818,10 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev)
    > if (err)
    > return err;
    >
    > + err = pm_runtime_force_resume(dev);
    > + if (err < 0)
    > + return err;
    > +
    > i2c_mark_adapter_resumed(&i2c_dev->adapter);
    >
    > return 0;
    >

    It just occurred to me that this patch needs to marked as fixes for the
    "i2c: tegra: Move suspend handling to NOIRQ phase" patch because it
    broke runtime PM enable-refcount by disabling clock/pinmux on resume
    from suspend. For now I'll wait for the review comments. Please review,
    thanks in advance.

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