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

[Jonathan Cameron]

On Sat, 16 May 2026 10:38:02 -0500
David Lechner <dlechner@xxxxxxxxxxxx> wrote:

> On 5/14/26 9:37 AM, Stepan Ionichev 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@xxxxxxxxx>
> > ---
> > 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)
> 
> This can just be ret != 12.
Doh. I missed that completely.  Tweaked.

> 
> > +		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);
> >  
>