diff mbox series

[1/5] media: v4l2-async: Document asd allocation requirements

Message ID 20200811205939.19550-2-laurent.pinchart+renesas@ideasonboard.com (mailing list archive)
State New, archived
Headers show
Series media: Fix asd dynamic allocation | expand

Commit Message

Laurent Pinchart Aug. 11, 2020, 8:59 p.m. UTC
The v4l2_async_notifier_add_subdev() function requires the asd pointer
it receives to be allocated dynamically, but doesn't explicitly say so.
Only one driver out of 13 get its right (atmel-sama5d2-isc.c, but with
memory leaks in the error paths), clearly showing we have an issue.

Update the v4l2_async_notifier_add_subdev() documentation to clearly
state the allocation requirement. Whether this will be enough to avoid
new offending code isn't certain, but it's a good first step
nonetheless.

Fixes: 9ca465312132 ("media: v4l: fwnode: Support generic parsing of graph endpoints in a device")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 include/media/v4l2-async.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Laurent Pinchart Sept. 8, 2020, 5:08 a.m. UTC | #1
Gentle ping for reviews.

On Tue, Aug 11, 2020 at 11:59:35PM +0300, Laurent Pinchart wrote:
> The v4l2_async_notifier_add_subdev() function requires the asd pointer
> it receives to be allocated dynamically, but doesn't explicitly say so.
> Only one driver out of 13 get its right (atmel-sama5d2-isc.c, but with
> memory leaks in the error paths), clearly showing we have an issue.
> 
> Update the v4l2_async_notifier_add_subdev() documentation to clearly
> state the allocation requirement. Whether this will be enough to avoid
> new offending code isn't certain, but it's a good first step
> nonetheless.
> 
> Fixes: 9ca465312132 ("media: v4l: fwnode: Support generic parsing of graph endpoints in a device")
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
>  include/media/v4l2-async.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> index 8319284c93cb..d6e31234826f 100644
> --- a/include/media/v4l2-async.h
> +++ b/include/media/v4l2-async.h
> @@ -154,8 +154,9 @@ void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
>   * @notifier: pointer to &struct v4l2_async_notifier
>   * @asd: pointer to &struct v4l2_async_subdev
>   *
> - * Call this function before registering a notifier to link the
> - * provided asd to the notifiers master @asd_list.
> + * Call this function before registering a notifier to link the provided @asd to
> + * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as
> + * it will be freed by the framework when the notifier is destroyed.
>   */
>  int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
>  				   struct v4l2_async_subdev *asd);
Kieran Bingham Sept. 16, 2020, 3:44 p.m. UTC | #2
Hi Laurent,

On 11/08/2020 21:59, Laurent Pinchart wrote:
> The v4l2_async_notifier_add_subdev() function requires the asd pointer
> it receives to be allocated dynamically, but doesn't explicitly say so.
> Only one driver out of 13 get its right (atmel-sama5d2-isc.c, but with
> memory leaks in the error paths), clearly showing we have an issue.
> 
> Update the v4l2_async_notifier_add_subdev() documentation to clearly
> state the allocation requirement. Whether this will be enough to avoid
> new offending code isn't certain, but it's a good first step
> nonetheless.
> 
> Fixes: 9ca465312132 ("media: v4l: fwnode: Support generic parsing of graph endpoints in a device")
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Seems reasonable to me:

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

> ---
>  include/media/v4l2-async.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> index 8319284c93cb..d6e31234826f 100644
> --- a/include/media/v4l2-async.h
> +++ b/include/media/v4l2-async.h
> @@ -154,8 +154,9 @@ void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
>   * @notifier: pointer to &struct v4l2_async_notifier
>   * @asd: pointer to &struct v4l2_async_subdev
>   *
> - * Call this function before registering a notifier to link the
> - * provided asd to the notifiers master @asd_list.
> + * Call this function before registering a notifier to link the provided @asd to
> + * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as
> + * it will be freed by the framework when the notifier is destroyed.
>   */
>  int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
>  				   struct v4l2_async_subdev *asd);
>
diff mbox series

Patch

diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 8319284c93cb..d6e31234826f 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -154,8 +154,9 @@  void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
  * @notifier: pointer to &struct v4l2_async_notifier
  * @asd: pointer to &struct v4l2_async_subdev
  *
- * Call this function before registering a notifier to link the
- * provided asd to the notifiers master @asd_list.
+ * Call this function before registering a notifier to link the provided @asd to
+ * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as
+ * it will be freed by the framework when the notifier is destroyed.
  */
 int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 				   struct v4l2_async_subdev *asd);