Re: [PATCH v2] iio: proximity: vcnl3020: fix ISR bitmask check in IRQ handler

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 24 Aug 2026 05:29:07 +0100
Salah Triki <salah.triki@gmail.com> wrote:

> The threaded IRQ handler contained multiple issues in handling interrupt
> events and clearing status flags:
> 
> 1. ISR bit check: The handler incorrectly checked the Interrupt Status
>    Register (VCNL_ISR) against VCNL_ICR_THRES_EN (BIT(1)), which is a
>    bitmask meant for the Control Register (VCNL_PS_ICR). In VCNL_ISR,
>    BIT(1) corresponds only to low-threshold interrupts. A high-threshold
>    interrupt (VCNL_INT_TH_HI, BIT(0)) on its own was completely ignored and
>    returned IRQ_NONE.
> 
> 2. Event direction & channel index: The handler unconditionally pushed a
>    RISING event code on channel index 1. The driver only registers a single
>    proximity channel (index 0), and low-threshold interrupts should be
>    reported with IIO_EV_DIR_FALLING.
> 
> 3. ISR clearing: The write-back to acknowledge the interrupt only preserved
>    BIT(1) instead of masking against both valid status bits.
> 
> Fix this by checking both VCNL_INT_TH_HI and VCNL_INT_TH_LOW bits in
> VCNL_ISR, pushing separate IIO events with the correct direction and
> channel index (0), and properly clearing handled status bits.
> 
> Fixes: 3363fbbe19e5 ("iio: proximity: vcnl3020: add periodic mode")
> Signed-off-by: Salah Triki <salah.triki@gmail.com>

Trying an active address that is hopefully the same Ivan!

This looks fine to me, but I'd ideally like input from Ivan.

Jonathan

> ---
> Changes since v1:
>   - Extended the patch to fix additional bugs found in vcnl3020_handle_irq_thread():
>     - Corrected event directions (RISING for high threshold, FALLING for low threshold).
>     - Fixed channel index from 1 to 0 (matching single proximity channel).
>     - Corrected ISR W1C clear logic for both HI and LOW bits.
>   - Updated commit message to detail all IRQ handler fixes.
> 
>  drivers/iio/proximity/vcnl3020.c | 24 +++++++++++++++++-------
>  1 file changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iio/proximity/vcnl3020.c b/drivers/iio/proximity/vcnl3020.c
> index 7f417372566a..d0b8f429999f 100644
> --- a/drivers/iio/proximity/vcnl3020.c
> +++ b/drivers/iio/proximity/vcnl3020.c
> @@ -584,16 +584,26 @@ static irqreturn_t vcnl3020_handle_irq_thread(int irq, void *p)
>  		return IRQ_HANDLED;
>  	}
>  
> -	if (!(isr & VCNL_ICR_THRES_EN))
> +	if (!(isr & (VCNL_INT_TH_HI | VCNL_INT_TH_LOW)))
>  		return IRQ_NONE;
>  
> -	iio_push_event(indio_dev,
> -		       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 1,
> -				            IIO_EV_TYPE_THRESH,
> -				            IIO_EV_DIR_RISING),
> -		       iio_get_time_ns(indio_dev));
> +	if (isr & VCNL_INT_TH_HI) {
> +		iio_push_event(indio_dev,
> +			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
> +						    IIO_EV_TYPE_THRESH,
> +						    IIO_EV_DIR_RISING),
> +			       iio_get_time_ns(indio_dev));
> +	}
> +
> +	if (isr & VCNL_INT_TH_LOW) {
> +		iio_push_event(indio_dev,
> +			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
> +						    IIO_EV_TYPE_THRESH,
> +						    IIO_EV_DIR_FALLING),
> +			       iio_get_time_ns(indio_dev));
> +	}
>  
> -	rc = regmap_write(data->regmap, VCNL_ISR, isr & VCNL_ICR_THRES_EN);
> +	rc = regmap_write(data->regmap, VCNL_ISR, isr & (VCNL_INT_TH_HI | VCNL_INT_TH_LOW));
>  	if (rc)
>  		dev_err(data->dev, "Error (%d) writing in reg (0x%x)\n",
>  			rc, VCNL_ISR);