On 3/20/20 11:40 AM, Alexandru Ardelean wrote:
From: Lars-Peter Clausen <lars@xxxxxxxxxx>
Before activating a buffer make sure that at least one channel is enabled.
Activating a buffer with 0 channels enabled doesn't make too much sense and
disallowing this case makes sure that individual driver don't have to add
special case code to handle it.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
---
* Found this relic-patch in our tree, from 6 years ago:
https://github.com/analogdevicesinc/linux/commit/6d680e49d459c
It got moved around a bit, and this is the current form in the ADI tree.
So, this is also a bit of an RFC, but if the idea is valid, maybe it's
worth considering upstream. I don't know of any arguments against it,
but I could be surprised.
Hm, a bit weird that this one never made it upstream considering how
simple it is.
Did you check that the issue still occurs? I can't see anything in the
code that prevents it, but who knows, maybe it was fixed by something else.
drivers/iio/industrialio-buffer.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 4ada5592aa2b..f222a118d0d3 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1031,6 +1031,12 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
return ret;
if (insert_buffer) {
+ if (bitmap_empty(insert_buffer->scan_mask,
+ indio_dev->masklength)) {
+ ret = -EINVAL;
+ goto err_free_config;
+ }
Since the check is so simple it might make sense to do it as the very
first thing before iio_verify_update().
+
ret = iio_buffer_request_update(indio_dev, insert_buffer);
if (ret)
goto err_free_config;
