Re: [PATCH v1] iio: adc: ad_sigma_delta: Clear pending interrupts before enable

From: Jonathan Cameron
Date: Sat Apr 06 2024 - 12:17:50 EST


On Thu, 4 Apr 2024 19:51:26 +0200
Markus Burri <markus.burri@xxxxxx> wrote:

Hi Markus,


> For device will enable and disable irq contiously like AD7195,
> it use DOUT/RDY pin for both SPI transfer and data ready.
> It will disable irq during SPI transfer, and re-eanble irq after SPI transfer.
> That may cause irq status bit set to 1 during spi transfer.

Superficially that sounds like it might be an irq driver bug to me...
Or just possibly an irq chip doing lazy disabling?

>
> When the active condition has been detected, the corresponding bit
> remains set until cleared by software. Status flags are cleared
> by writing a 1 to the corresponding bit position.
>
> Signed-off-by: Markus Burri <markus.burri@xxxxxx>

I'll need an appropriate ADI ack for this one.

It seems highly unusual to be calling a generic irqchip related function in a
driver (there are no other such users). So this seems unlikely to be
the right fix for this particular problem.

> ---
> drivers/iio/adc/ad_sigma_delta.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
> index a602429cdde4..59544c39642a 100644
> --- a/drivers/iio/adc/ad_sigma_delta.c
> +++ b/drivers/iio/adc/ad_sigma_delta.c
> @@ -515,6 +515,10 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
>
> irq_handled:
> iio_trigger_notify_done(indio_dev->trig);
> + /*
> + * ACK pending interrupts from spi transfer.

Single line comment format would be fine here.

> + */
> + irq_gc_ack_set_bit(irq_get_irq_data(sigma_delta->spi->irq));
> sigma_delta->irq_dis = false;
> enable_irq(sigma_delta->spi->irq);
>