From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Lars-Peter Clausen <lars@metafoo.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Stable@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: [PATCH 5.10 112/132] iio: kxsd9: Dont return error code in trigger handler
Date:   Mon, 13 Dec 2021 10:30:53 +0100
Message-Id: <20211213092942.940765515@linuxfoundation.org>
In-Reply-To: <20211213092939.074326017@linuxfoundation.org>
References: <20211213092939.074326017@linuxfoundation.org>
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From: Lars-Peter Clausen <lars@metafoo.de>

commit 45febe0d63917ee908198c5be08511c64ee1790a upstream.

IIO trigger handlers need to return one of the irqreturn_t values.
Returning an error code is not supported.

The kxsd9 interrupt handler returns an error code if reading the data
registers fails. In addition when exiting due to an error the trigger
handler does not call `iio_trigger_notify_done()`. Which when not done
keeps the triggered disabled forever.

Modify the code so that the function returns a valid irqreturn_t value as
well as calling `iio_trigger_notify_done()` on all exit paths.

Since we can't return the error code make sure to at least log it as part
of the error message.

Fixes: 0427a106a98a ("iio: accel: kxsd9: Add triggered buffer handling")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20211024171251.22896-2-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/iio/accel/kxsd9.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/iio/accel/kxsd9.c
+++ b/drivers/iio/accel/kxsd9.c
@@ -224,14 +224,14 @@ static irqreturn_t kxsd9_trigger_handler
 			       hw_values.chan,
 			       sizeof(hw_values.chan));
 	if (ret) {
-		dev_err(st->dev,
-			"error reading data\n");
-		return ret;
+		dev_err(st->dev, "error reading data: %d\n", ret);
+		goto out;
 	}
 
 	iio_push_to_buffers_with_timestamp(indio_dev,
 					   &hw_values,
 					   iio_get_time_ns(indio_dev));
+out:
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;