[PATCH v3 1/8] media: v4l2-ioctl: Fix check_ext_ctrls

[Ricardo Ribalda <ribalda@chromium.org>]

Drivers that do not use the ctrl-framework use this function instead.

- Return error when handling of REQUEST_VAL.
- Do not check for multiple classes when getting the DEF_VAL.

Fixes v4l2-compliance:
Control ioctls (Input 0):
		fail: v4l2-test-controls.cpp(813): doioctl(node, VIDIOC_G_EXT_CTRLS, &ctrls)
	test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL

Cc: stable@vger.kernel.org
Fixes: 6fa6f831f095 ("media: v4l2-ctrls: add core request support")
Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-ioctl.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 31d1342e61e8..9406e90ff805 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -917,15 +917,24 @@ static int check_ext_ctrls(struct v4l2_ext_controls *c, int allow_priv)
 	for (i = 0; i < c->count; i++)
 		c->controls[i].reserved2[0] = 0;
 
-	/* V4L2_CID_PRIVATE_BASE cannot be used as control class
-	   when using extended controls.
-	   Only when passed in through VIDIOC_G_CTRL and VIDIOC_S_CTRL
-	   is it allowed for backwards compatibility.
-	 */
-	if (!allow_priv && c->which == V4L2_CID_PRIVATE_BASE)
-		return 0;
-	if (!c->which)
+	switch (c->which) {
+	case V4L2_CID_PRIVATE_BASE:
+		/*
+		 * V4L2_CID_PRIVATE_BASE cannot be used as control class
+		 * when using extended controls.
+		 * Only when passed in through VIDIOC_G_CTRL and VIDIOC_S_CTRL
+		 * is it allowed for backwards compatibility.
+		*/
+		if (!allow_priv)
+			return 0;
+		break;
+	case V4L2_CTRL_WHICH_DEF_VAL:
+	case V4L2_CTRL_WHICH_CUR_VAL:
 		return 1;
+	case V4L2_CTRL_WHICH_REQUEST_VAL:
+		return 0;
+	}
+
 	/* Check that all controls are from the same control class. */
 	for (i = 0; i < c->count; i++) {
 		if (V4L2_CTRL_ID2WHICH(c->controls[i].id) != c->which) {
-- 
2.31.0.rc2.261.g7f71774620-goog