Re: [PATCH v2] iio: proximity: vl53l0x: notify trigger and clear IRQ on error paths

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 14 May 2026 19:37:10 +0500
Stepan Ionichev <sozdayvek@gmail.com> wrote:

> vl53l0x_trigger_handler() returns directly on the I2C read failure
> paths without calling iio_trigger_notify_done() or vl53l0x_clear_irq().
> 
> A single transient i2c_smbus_read_i2c_block_data() failure (negative
> errno or a short read) therefore leaves two pieces of state behind:
> 
>   - iio_trigger_notify_done() never decrements the trigger's use_count,
>     so iio_trigger_poll_nested() silently drops further dispatches
>     (see industrialio-trigger.c, the !atomic_read(&trig->use_count)
>     guard);
>   - vl53l0x_clear_irq() never writes SYSTEM_INTERRUPT_CLEAR, so the
>     chip keeps the DRDY interrupt asserted.
> 
> The sensor's buffer mode stays wedged from then on, recoverable only
> by re-binding the driver. The sibling driver vl53l1x-i2c.c handles
> exactly the same case correctly by jumping to a "notify_and_clear_irq"
> label that always calls both helpers; mirror that here.
> 
> The bogus negative-int return value cast to irqreturn_t also goes
> away as a side effect.
> 
> Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support")
> Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Applied and marked for stable, not so much because it wedges (as probably
won't recover anyway) but more to get rid of a negative error return in an
irq handler.


> ---
> v2:
> - Drop the cited error-path code from the commit body; the diff
>   already shows it (per Andy)
> 
>  drivers/iio/proximity/vl53l0x-i2c.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
> index ad3e46d47..7acb94acc 100644
> --- a/drivers/iio/proximity/vl53l0x-i2c.c
> +++ b/drivers/iio/proximity/vl53l0x-i2c.c
> @@ -87,15 +87,14 @@ static irqreturn_t vl53l0x_trigger_handler(int irq, void *priv)
>  	ret = i2c_smbus_read_i2c_block_data(data->client,
>  					VL_REG_RESULT_RANGE_STATUS,
>  					sizeof(buffer), buffer);
> -	if (ret < 0)
> -		return ret;
> -	else if (ret != 12)
> -		return -EREMOTEIO;
> +	if (ret < 0 || ret != 12)
> +		goto done;
>  
>  	scan.chan = get_unaligned_be16(&buffer[10]);
>  	iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
>  				    iio_get_time_ns(indio_dev));
>  
> +done:
>  	iio_trigger_notify_done(indio_dev->trig);
>  	vl53l0x_clear_irq(data);
>