Hi Laurent,
Thanks for your work.
On 2020-03-15 14:55:11 +0200, Laurent Pinchart wrote:
> fwnode matching was designed to match on nodes corresponding to a
> device. Some drivers, however, needed to match on endpoints, and have
> passed endpoint fwnodes to v4l2-async. This works when both the subdev
> and the notifier use the same fwnode types (endpoint or device), but
> makes drivers that use different types incompatible.
>
> Fix this by extending the fwnode match to handle fwnodes of different
> types. When the types (deduced from the node name) are different,
> retrieve the device fwnode for the side that provides an endpoint
> fwnode, and compare it with the device fwnode provided by the other
> side. This allows interoperability between all drivers, regardless of
> which type of fwnode they use for matching.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
I tested this on R-Car CSI-2 and ADV748x without any regressions. As
Jacopo already pointed out it's similar to what have been tried before
and have the potential problem for new transmitters registering multiple
endpoints (like ADV748x) being used together with older receivers who
register a single device node in v4l-async. But this do not introduce
any regressions and is a good first step to move everything to endpoint
matching.
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Maybe a info message should be logged if a match is made between
endpoint and node? It would make it easy to spot if one needs to debug a
miss match and would be a clear message one driver should be moved to
endpoint matching. Maybe adding such a log message would count as a
regression for some.
> ---
> This has been compile-tested only. Prabhakar, could you check if it
> fixes your issue ?
>
> drivers/media/v4l2-core/v4l2-async.c | 42 +++++++++++++++++++++++++++-
> 1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 8bde33c21ce4..995e5464cba7 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -71,7 +71,47 @@ static bool match_devname(struct v4l2_subdev *sd,
>
> static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> {
> - return sd->fwnode == asd->match.fwnode;
> + struct fwnode_handle *other_fwnode;
> + struct fwnode_handle *dev_fwnode;
> + bool asd_fwnode_is_ep;
> + bool sd_fwnode_is_ep;
> + const char *name;
> +
> + /*
> + * Both the subdev and the async subdev can provide either an endpoint
> + * fwnode or a device fwnode. Start with the simple case of direct
> + * fwnode matching.
> + */
> + if (sd->fwnode == asd->match.fwnode)
> + return true;
> +
> + /*
> + * Otherwise, check if the sd fwnode and the asd fwnode refer to an
> + * endpoint or a device. If they're of the same type, there's no match.
> + */
> + name = fwnode_get_name(sd->fwnode);
> + sd_fwnode_is_ep = name && strstarts(name, "endpoint");
> + name = fwnode_get_name(asd->match.fwnode);
> + asd_fwnode_is_ep = name && strstarts(name, "endpoint");
> +
> + if (sd_fwnode_is_ep == asd_fwnode_is_ep)
> + return false;
> +
> + /*
> + * The sd and asd fwnodes are of different types. Get the device fwnode
> + * parent of the endpoint fwnode, and compare it with the other fwnode.
> + */
> + if (sd_fwnode_is_ep) {
> + dev_fwnode = fwnode_graph_get_port_parent(sd->fwnode);
> + other_fwnode = asd->match.fwnode;
> + } else {
> + dev_fwnode = fwnode_graph_get_port_parent(asd->match.fwnode);
> + other_fwnode = sd->fwnode;
> + }
> +
> + fwnode_handle_put(dev_fwnode);
> +
> + return dev_fwnode == other_fwnode;
> }
>
> static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> --
> Regards,
>
> Laurent Pinchart
>
--
Regards,
Niklas Söderlund
