lkml.org 
[lkml]   [2019]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.18 22/52] mfd: tps6586x: Handle interrupts on suspend
    Date
    3.18-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Jonathan Hunter <jonathanh@nvidia.com>

    commit ac4ca4b9f4623ba5e1ea7a582f286567c611e027 upstream.

    The tps6586x driver creates an irqchip that is used by its various child
    devices for managing interrupts. The tps6586x-rtc device is one of its
    children that uses the tps6586x irqchip. When using the tps6586x-rtc as
    a wake-up device from suspend, the following is seen:

    PM: Syncing filesystems ... done.
    Freezing user space processes ... (elapsed 0.001 seconds) done.
    OOM killer disabled.
    Freezing remaining freezable tasks ... (elapsed 0.000 seconds) done.
    Disabling non-boot CPUs ...
    Entering suspend state LP1
    Enabling non-boot CPUs ...
    CPU1 is up
    tps6586x 3-0034: failed to read interrupt status
    tps6586x 3-0034: failed to read interrupt status

    The reason why the tps6586x interrupt status cannot be read is because
    the tps6586x interrupt is not masked during suspend and when the
    tps6586x-rtc interrupt occurs, to wake-up the device, the interrupt is
    seen before the i2c controller has been resumed in order to read the
    tps6586x interrupt status.

    The tps6586x-rtc driver sets it's interrupt as a wake-up source during
    suspend, which gets propagated to the parent tps6586x interrupt.
    However, the tps6586x-rtc driver cannot disable it's interrupt during
    suspend otherwise we would never be woken up and so the tps6586x must
    disable it's interrupt instead.

    Prevent the tps6586x interrupt handler from executing on exiting suspend
    before the i2c controller has been resumed by disabling the tps6586x
    interrupt on entering suspend and re-enabling it on resuming from
    suspend.

    Cc: stable@vger.kernel.org
    Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
    Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
    Tested-by: Dmitry Osipenko <digetx@gmail.com>
    Acked-by: Thierry Reding <treding@nvidia.com>
    Signed-off-by: Lee Jones <lee.jones@linaro.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/mfd/tps6586x.c | 24 ++++++++++++++++++++++++
    1 file changed, 24 insertions(+)

    --- a/drivers/mfd/tps6586x.c
    +++ b/drivers/mfd/tps6586x.c
    @@ -601,6 +601,29 @@ static int tps6586x_i2c_remove(struct i2
    return 0;
    }

    +static int __maybe_unused tps6586x_i2c_suspend(struct device *dev)
    +{
    + struct tps6586x *tps6586x = dev_get_drvdata(dev);
    +
    + if (tps6586x->client->irq)
    + disable_irq(tps6586x->client->irq);
    +
    + return 0;
    +}
    +
    +static int __maybe_unused tps6586x_i2c_resume(struct device *dev)
    +{
    + struct tps6586x *tps6586x = dev_get_drvdata(dev);
    +
    + if (tps6586x->client->irq)
    + enable_irq(tps6586x->client->irq);
    +
    + return 0;
    +}
    +
    +static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_i2c_suspend,
    + tps6586x_i2c_resume);
    +
    static const struct i2c_device_id tps6586x_id_table[] = {
    { "tps6586x", 0 },
    { },
    @@ -612,6 +635,7 @@ static struct i2c_driver tps6586x_driver
    .name = "tps6586x",
    .owner = THIS_MODULE,
    .of_match_table = of_match_ptr(tps6586x_of_match),
    + .pm = &tps6586x_pm_ops,
    },
    .probe = tps6586x_i2c_probe,
    .remove = tps6586x_i2c_remove,

    \
     
     \ /
      Last update: 2019-01-24 21:19    [W:2.156 / U:0.088 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site