From 98c015535a0da65369585e4377dd0e3d1fdf6a65 Mon Sep 17 00:00:00 2001
From: Ricardo Ribalda <ribalda@chromium.org>
Date: Mon, 29 Apr 2024 15:04:42 +0000
Subject: [PATCH] media: uvcvideo: Refactor iterators

BugLink: https://bugs.launchpad.net/bugs/2114239

[ Upstream commit 64627daf0c5f7838111f52bbbd1a597cb5d6871a ]

Avoid using the iterators after the list_for_each() constructs.
This patch should be a NOP, but makes cocci, happier:

drivers/media/usb/uvc/uvc_ctrl.c:1861:44-50: ERROR: invalid reference to the index variable of the iterator on line 1850
drivers/media/usb/uvc/uvc_ctrl.c:2195:17-23: ERROR: invalid reference to the index variable of the iterator on line 2179

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Stable-dep-of: d9fecd096f67 ("media: uvcvideo: Only save async fh if success")
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit bd747c0a1a0dbab264e27d53fb0c757011eb92f0 linux-6.6.y)
[nwager: Pick 6.6.80 patches for 6.12.14 stable updates so we don't break
up the patchset "media: uvcvideo: Two +1 fixes for async controls"]
Signed-off-by: Noah Wager <noah.wager@canonical.com>
Signed-off-by: Mehmet Basaran <mehmet.basaran@canonical.com>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index ce70e96b8fb5..f78e0c02b337 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1848,16 +1848,18 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
 	list_for_each_entry(entity, &chain->entities, chain) {
 		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback,
 					     &err_ctrl);
-		if (ret < 0)
+		if (ret < 0) {
+			if (ctrls)
+				ctrls->error_idx =
+					uvc_ctrl_find_ctrl_idx(entity, ctrls,
+							       err_ctrl);
 			goto done;
+		}
 	}
 
 	if (!rollback)
 		uvc_ctrl_send_events(handle, ctrls->controls, ctrls->count);
 done:
-	if (ret < 0 && ctrls)
-		ctrls->error_idx = uvc_ctrl_find_ctrl_idx(entity, ctrls,
-							  err_ctrl);
 	mutex_unlock(&chain->ctrl_mutex);
 	return ret;
 }
@@ -2170,7 +2172,7 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
 int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
 	struct uvc_xu_control_query *xqry)
 {
-	struct uvc_entity *entity;
+	struct uvc_entity *entity, *iter;
 	struct uvc_control *ctrl;
 	unsigned int i;
 	bool found;
@@ -2180,16 +2182,16 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
 	int ret;
 
 	/* Find the extension unit. */
-	found = false;
-	list_for_each_entry(entity, &chain->entities, chain) {
-		if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
-		    entity->id == xqry->unit) {
-			found = true;
+	entity = NULL;
+	list_for_each_entry(iter, &chain->entities, chain) {
+		if (UVC_ENTITY_TYPE(iter) == UVC_VC_EXTENSION_UNIT &&
+		    iter->id == xqry->unit) {
+			entity = iter;
 			break;
 		}
 	}
 
-	if (!found) {
+	if (!entity) {
 		uvc_dbg(chain->dev, CONTROL, "Extension unit %u not found\n",
 			xqry->unit);
 		return -ENOENT;