FAILED: patch "[PATCH] media: uvcvideo: Only save async fh if success" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x d9fecd096f67a4469536e040a8a10bbfb665918b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025021009-blazing-throwback-e62a@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d9fecd096f67a4469536e040a8a10bbfb665918b Mon Sep 17 00:00:00 2001
From: Ricardo Ribalda <[email protected]>
Date: Tue, 3 Dec 2024 21:20:08 +0000
Subject: [PATCH] media: uvcvideo: Only save async fh if success

Now we keep a reference to the active fh for any call to uvc_ctrl_set, regardless if it is an actual set or if it is a just a try or if the device refused the operation.

We should only keep the file handle if the device actually accepted applying the operation.

index bab9fdac98e6..e0806641a8d0 100644
@@ -1811,7 +1811,10 @@ int uvc_ctrl_begin(struct uvc_video_chain *chain)
 }
 
 static int uvc_ctrl_commit_entity(struct uvc_device *dev,
-	struct uvc_entity *entity, int rollback, struct uvc_control **err_ctrl)
+				  struct uvc_fh *handle,
+				  struct uvc_entity *entity,
+				  int rollback,
+				  struct uvc_control **err_ctrl)
 {
 	struct uvc_control *ctrl;
 	unsigned int i;

@@ -1859,6 +1862,10 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
 				*err_ctrl = ctrl;
 			return ret;
 		}
+
+		if (!rollback && handle &&
+		    ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
+			ctrl->handle = handle;
 	}
 
 	return 0;

@@ -1895,8 +1902,8 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
 
 	/* Find the control. */
 	list_for_each_entry(entity, &chain->entities, chain) {
-		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback,
-					     &err_ctrl);
+		ret = uvc_ctrl_commit_entity(chain->dev, handle, entity,
+					     rollback, &err_ctrl);
 		if (ret < 0) {
 			if (ctrls)
 				ctrls->error_idx =

@@ -2046,9 +2053,6 @@ int uvc_ctrl_set(struct uvc_fh *handle,
 	mapping->set(mapping, value,
 		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
 
-	if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
-		ctrl->handle = handle;
-
 	ctrl->dirty = 1;
 	ctrl->modified = 1;
 	return 0;

@@ -2377,7 +2381,7 @@ int uvc_ctrl_restore_values(struct uvc_device *dev)
 			ctrl->dirty = 1;
 		}
 
-		ret = uvc_ctrl_commit_entity(dev, entity, 0, NULL);
+		ret = uvc_ctrl_commit_entity(dev, NULL, entity, 0, NULL);
 		if (ret < 0)
 			return ret;
 	}

Now we keep a reference to the active fh for any call to uvc_ctrl_set, regardless if it is an actual set or if it is a just a try or if the device refused the operation.

We should only keep the file handle if the device actually accepted applying the operation.

---
 drivers/media/usb/uvc/uvc_ctrl.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

index e3457449faae..9fc84f0ac047 100644
@@ -1528,7 +1528,9 @@ int uvc_ctrl_begin(struct uvc_video_chain *chain)
 }
 
 static int uvc_ctrl_commit_entity(struct uvc_device *dev,
-	struct uvc_entity *entity, int rollback)
+				  struct uvc_fh *handle,
+				  struct uvc_entity *entity,
+				  int rollback)
 {
 	struct uvc_control *ctrl;
 	unsigned int i;

@@ -1572,6 +1574,10 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
 
 		if (ret < 0)
 			return ret;
+
+		if (!rollback && handle &&
+		    ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
+			ctrl->handle = handle;
 	}
 
 	return 0;

@@ -1587,7 +1593,8 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
 
 	/* Find the control. */
 	list_for_each_entry(entity, &chain->entities, chain) {
-		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback);
+		ret = uvc_ctrl_commit_entity(chain->dev, handle, entity,
+					     rollback);
 		if (ret < 0)
 			goto done;
 	}

@@ -1711,9 +1718,6 @@ int uvc_ctrl_set(struct uvc_fh *handle,
 	mapping->set(mapping, value,
 		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
 
-	if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
-		ctrl->handle = handle;
-
 	ctrl->dirty = 1;
 	ctrl->modified = 1;
 	return 0;

@@ -2042,7 +2046,7 @@ int uvc_ctrl_restore_values(struct uvc_device *dev)
 			ctrl->dirty = 1;
 		}
 
-		ret = uvc_ctrl_commit_entity(dev, entity, 0);
+		ret = uvc_ctrl_commit_entity(dev, NULL, entity, 0);
 		if (ret < 0)
 			return ret;
 	}

2.48.1.711.g2feabab25a-goog

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: d9fecd096f67a4469536e040a8a10bbfb665918b

Status in newer kernel trees:
6.13.y | Present (different SHA1: e515ccef73e2) 6.12.y | Present (different SHA1: 34fb9eb31d66) 6.6.y | Present (different SHA1: 08384382e1db) 6.1.y | Present (different SHA1: 050053a7c0ad)

Note: The patch differs from the upstream commit:
---
1: d9fecd096f67a ! 1: 44f5b59535218 media: uvcvideo: Only save async fh if success

    @@ Commit message
         Link: https://lore.kernel.org/r/[email protected]
         Signed-off-by: Laurent Pinchart <[email protected]>
         Signed-off-by: Mauro Carvalho Chehab <[email protected]>
    +    (cherry picked from commit d9fecd096f67a4469536e040a8a10bbfb665918b)
     
      ## drivers/media/usb/uvc/uvc_ctrl.c ##
     @@ drivers/media/usb/uvc/uvc_ctrl.c: int uvc_ctrl_begin(struct uvc_video_chain *chain)
      }
      
      static int uvc_ctrl_commit_entity(struct uvc_device *dev,
    --	struct uvc_entity *entity, int rollback, struct uvc_control **err_ctrl)
    +-	struct uvc_entity *entity, int rollback)
     +				  struct uvc_fh *handle,
     +				  struct uvc_entity *entity,
    -+				  int rollback,
    -+				  struct uvc_control **err_ctrl)
    ++				  int rollback)
      {
      	struct uvc_control *ctrl;
      	unsigned int i;
     @@ drivers/media/usb/uvc/uvc_ctrl.c: static int uvc_ctrl_commit_entity(struct uvc_device *dev,
    - 				*err_ctrl = ctrl;
    + 
    + 		if (ret < 0)
      			return ret;
    - 		}
     +
     +		if (!rollback && handle &&
     +		    ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
    @@ drivers/media/usb/uvc/uvc_ctrl.c: int __uvc_ctrl_commit(struct uvc_fh *handle, i
      
      	/* Find the control. */
      	list_for_each_entry(entity, &chain->entities, chain) {
    --		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback,
    --					     &err_ctrl);
    +-		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback);
     +		ret = uvc_ctrl_commit_entity(chain->dev, handle, entity,
    -+					     rollback, &err_ctrl);
    - 		if (ret < 0) {
    - 			if (ctrls)
    - 				ctrls->error_idx =
    ++					     rollback);
    + 		if (ret < 0)
    + 			goto done;
    + 	}
     @@ drivers/media/usb/uvc/uvc_ctrl.c: int uvc_ctrl_set(struct uvc_fh *handle,
      	mapping->set(mapping, value,
      		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
    @@ drivers/media/usb/uvc/uvc_ctrl.c: int uvc_ctrl_restore_values(struct uvc_device
      			ctrl->dirty = 1;
      		}
      
    --		ret = uvc_ctrl_commit_entity(dev, entity, 0, NULL);
    -+		ret = uvc_ctrl_commit_entity(dev, NULL, entity, 0, NULL);
    +-		ret = uvc_ctrl_commit_entity(dev, entity, 0);
    ++		ret = uvc_ctrl_commit_entity(dev, NULL, entity, 0);
      		if (ret < 0)
      			return ret;
      	}

---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y        |  Success    |  Success   |