Re: [PATCH 12/15] iio: imu: inv_mpu6050: don't disable the IRQ under lock

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 27 Oct 2026 17:19:16 +0100
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> From: Josef Bacik <josef@toxicpanda.com>
> 
> If the chip is a wake-up source, inv_mpu_suspend() calls disable_irq() with
> st->lock held.  disable_irq() waits for the threaded handler, and
> inv_mpu6050_interrupt_handle() takes st->lock to read the interrupt
> status.  If the chip raises an interrupt while the system is being
> suspended, the handler waits for the lock, the suspend callback waits for
> the handler, and the suspend hangs.
> 
> Disable the interrupt once the lock has been dropped.
> 
> Fixes: 305914d01807 ("iio: imu: inv_mpu6050: add WoM suspend wakeup with low-power mode")
> Cc: stable <stable@kernel.org>
> Cc: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>

This seems correct to me, but waiting on Jean-Baptiste for
view from someone more familiar with the driver (and maybe
able to give it a sanity check test!)

> Cc: David Lechner <dlechner@baylibre.com>
> Cc: "Nuno Sá" <nuno.sa@analog.com>
> Cc: Andy Shevchenko <andy@kernel.org>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 38c3f3b398d4..0ae9d497ccfd 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -2166,7 +2166,7 @@ static int inv_mpu_resume(struct device *dev)
>  	return result;
>  }
>  
> -static int inv_mpu_suspend(struct device *dev)
> +static int __inv_mpu_suspend(struct device *dev, bool *disable)
>  {
>  	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct inv_mpu6050_state *st = iio_priv(indio_dev);
> @@ -2212,7 +2212,7 @@ static int inv_mpu_suspend(struct device *dev)
>  		if (result)
>  			return result;
>  		enable_irq_wake(st->irq);
> -		disable_irq(st->irq);
> +		*disable = true;
>  	} else {
>  		result = inv_mpu6050_set_power_itg(st, false);
>  		if (result)
> @@ -2223,6 +2223,21 @@ static int inv_mpu_suspend(struct device *dev)
>  	return 0;
>  }
>  
> +static int inv_mpu_suspend(struct device *dev)
> +{
> +	struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(dev));
> +	bool disable = false;
> +	int result;
> +
> +	result = __inv_mpu_suspend(dev, &disable);
> +
> +	/* Not under st->lock: this waits for the handler, which takes it */
> +	if (disable)
> +		disable_irq(st->irq);
> +
> +	return result;
> +}
> +
>  static int inv_mpu_runtime_suspend(struct device *dev)
>  {
>  	struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(dev));
>