Re: [PATCH v5] v4l2-async: Match parent devices

[jacopo mondi <jacopo@jmondi.org>]

Hi Kieran,

On Wed, Dec 06, 2017 at 02:58:39PM +0000, Kieran Bingham wrote:
> From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>
> Devices supporting multiple endpoints on a single device node must set
> their subdevice fwnode to the endpoint to allow distinct comparisons.
>
> Adapt the match_fwnode call to compare against the provided fwnodes
> first, but to also perform a cross reference comparison against the
> parent fwnodes of each other.
>
> This allows notifiers to pass the endpoint for comparison and still
> support existing subdevices which store their default parent device
> node.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

please append:

Reported-by: Jacopo Mondi <jacopo.mondi+renesas@jmondi.org>

Thanks
   j

>
> ---
>
> Hi Sakari,
>
> Since you signed-off on this patch - it has had to be reworked due to the
> changes on the of_node_full_name() functionality.
>
> I believe it is correct now to *just* do the pointer matching, as that matches
> the current implementation, and converting to device_nodes will be just as
> equal as the fwnodes, as they are simply containers.
>
> Let me know if you are happy to maintain your SOB on this patch - and if we need
> to work towards getting this integrated upstream, especially in light of your new
> endpoint matching work.
>
> --
> Regards
>
> Kieran
>
>
> v2:
>  - Added documentation comments
>  - simplified the OF match by adding match_fwnode_of()
>
> v3:
>  - Fix comments
>  - Fix sd_parent, and asd_parent usage
>
> v4:
>  - Clean up and simplify match_fwnode and comparisons
>
> v5:
>  - Updated for v4.15-rc1:
>    of_node no longer specifies a full path, and only returns the
>    basename with of_node_full_name(), thus this ends up matching
>    "endpoint" for all endpoints. Fall back to pointer matching,
>    whilst maintaining the parent comparisons.
> ---
>  drivers/media/v4l2-core/v4l2-async.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index fcadad305336..780bda70d8b3 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -71,9 +71,24 @@ static bool match_devname(struct v4l2_subdev *sd,
>  	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
>  }
>
> +/*
> + * As a measure to support drivers which have not been converted to use
> + * endpoint matching, we also find the parent devices for cross-matching.
> + *
> + * This also allows continued support for matching subdevices which will not
> + * have an endpoint themselves.
> + */
>  static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
>  {
> -	return sd->fwnode == asd->match.fwnode.fwnode;
> +	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
> +	struct fwnode_handle *sd_parent, *asd_parent;
> +
> +	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
> +	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);
> +
> +	return sd->fwnode == asd_fwnode ||
> +	       sd->fwnode == asd_parent ||
> +	       sd_parent == asd_fwnode;
>  }
>
>  static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> --
> 2.7.4
>