[PATCH 4.5 098/124] iio: fix config watermark initial value

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Irina Tirdea <irina.tirdea@xxxxxxxxx>

commit 1bef2c1d4e4fd92bdf8219b13ba97ba861618254 upstream.

config structure is set to 0 when updating the buffers, so by
default config->watermark will be 0. When computing the minimum
between config->watermark and the buffer->watermark or
insert_buffer-watermark, this will always be 0 regardless of the
value set by the user for the buffer.

Set as initial value for config->watermark the maximum allowed
value so that the minimum value will always be set from one of the
buffers.

Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx>
Fixes: f0566c0c405d ("iio: Set device watermark based on watermark of all
attached buffers")
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iio/industrialio-buffer.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -645,6 +645,7 @@ static int iio_verify_update(struct iio_
 	unsigned int modes;
 
 	memset(config, 0, sizeof(*config));
+	config->watermark = ~0;
 
 	/*
 	 * If there is just one buffer and we are removing it there is nothing