iio: hi8435: avoid garbage event at first enable (ee19ac34) · Commits · 戴 / test

Currently, driver generates events for channels if new reading differs from previous one. This "previous value" is initialized to zero, which results into event if value is constant-one. Fix that by initializing "previous value" by reading at event enable time. This provides reliable sequence for userspace: - enable event, - AFTER THAT read current value, - AFTER THAT each event will correspond to change. Signed-off-by:

Nikita Yushchenko <nikita.yoush@cogentembedded.com> Signed-off-by:

Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/hi8435.c

+13 −2

Original line number	Original line	Diff line number	Diff line
	@@ -141,10 +141,21 @@ static int hi8435_write_event_config(struct iio_dev *idev,
	enum iio_event_direction dir, int state)		enum iio_event_direction dir, int state)
	{		{
	struct hi8435_priv *priv = iio_priv(idev);		struct hi8435_priv *priv = iio_priv(idev);
			int ret;
			u32 tmp;

			if (state) {
			ret = hi8435_readl(priv, HI8435_SO31_0_REG, &tmp);
			if (ret < 0)
			return ret;
			if (tmp & BIT(chan->channel))
			priv->event_prev_val \|= BIT(chan->channel);
			else
			priv->event_prev_val &= ~BIT(chan->channel);

	priv->event_scan_mask &= ~BIT(chan->channel);
	if (state)
	priv->event_scan_mask \|= BIT(chan->channel);		priv->event_scan_mask \|= BIT(chan->channel);
			} else
			priv->event_scan_mask &= ~BIT(chan->channel);

	return 0;		return 0;
	}		}

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