[PATCH 6.1.y 2/2] iio: buffer: Fix wait_queue not being removed

[Sasha Levin <sashal@kernel.org>]

From: Nuno Sá <nuno.sa@analog.com>

[ Upstream commit 064234044056c93a3719d6893e6e5a26a94a61b6 ]

In the edge case where the IIO device is unregistered while we're
buffering, we were directly returning an error without removing the wait
queue. Instead, set 'ret' and break out of the loop.

Fixes: 9eeee3b0bf19 ("iio: Add output buffer support")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/industrialio-buffer.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index e02a4cb3d491c..d0bcb9c57f965 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -194,8 +194,10 @@ static ssize_t iio_buffer_write(struct file *filp, const char __user *buf,
 	written = 0;
 	add_wait_queue(&rb->pollq, &wait);
 	do {
-		if (!indio_dev->info)
-			return -ENODEV;
+		if (!indio_dev->info) {
+			ret = -ENODEV;
+			break;
+		}
 
 		if (!iio_buffer_space_available(rb)) {
 			if (signal_pending(current)) {
-- 
2.51.0