Re: [PATCH v3 2/2] iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 18 May 2026 12:55:33 +0000
"Sabau, Radu bogdan" <Radu.Sabau@analog.com> wrote:

> Hi everyone, I am responding to Sashiko's review here:
> 
> > -----Original Message-----
> > From: Radu Sabau via B4 Relay <devnull+radu.sabau.analog.com@kernel.org>
> > Sent: Monday, May 18, 2026 12:59 PM  
> 
> ...
> 
> > +	} else if (sigma_delta->info->has_registers) {
> >  		unsigned int status_reg;
> > 
> >  		ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_STATUS, 1,
> > &status_reg);
> > @@ -274,6 +279,8 @@ static int ad_sigma_delta_clear_pending_event(struct
> > ad_sigma_delta *sigma_delta
> >  			return ret;
> > 
> >  		pending_event = !(status_reg & AD_SD_REG_STATUS_RDY);
> > +	} else {
> > +		return 0;
> >  	}  
> 
> He is right about this one, the heap corruption may not be fully solved as a
> registerless device with num_resetclks = 0 confiugred with rdy-gpios could
> still have data_read_len = 0 further if GPIO indicates a pending event.
> 
> Perhaps I data_read_len == 0 should indeed be checked before attempting the
> dummy SPI transfer as suggested, right?
Indeed seems valid.   Make sure to leave some comments around on the
'why' of the extra check

> 
> > 
> >  	if (!pending_event)
> > @@ -578,6 +585,7 @@ static int ad_sd_buffer_postenable(struct iio_dev
> > *indio_dev)
> > 
> >  err_unlock:
> >  	sigma_delta->keep_cs_asserted = false;
> > +	ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);  
> 
> Also right about this one, it belongs in previous patch...
> 
> >  	sigma_delta->bus_locked = false;
> >  	spi_bus_unlock(sigma_delta->spi->controller);
> >  	spi_unoptimize_message(&sigma_delta->sample_msg);
> > 
> > --
> > 2.43.0
> >   
>