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

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	"Jacopo Mondi" <jacopo+renesas@jmondi.org>,
	"Kieran Bingham" <kieran.bingham+renesas@ideasonboard.com>,
	"Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
	"Ramesh Shanmugasundaram" <rashanmu@gmail.com>,
	"Sakari Ailus" <sakari.ailus@linux.intel.com>,
	"Steve Longerbeam" <slongerbeam@gmail.com>
Subject: Re: [PATCH 1/5] media: v4l2-async: Document asd allocation requirements
Date: Tue, 8 Sep 2020 08:08:05 +0300	[thread overview]
Message-ID: <20200908050805.GI6047@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20200811205939.19550-2-laurent.pinchart+renesas@ideasonboard.com>

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);

-- 
Regards,

Laurent Pinchart