Hi Niklas,
On Mon, Mar 16, 2020 at 10:40:12PM +0100, Niklas Söderlund wrote:
> 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.
WARN("FIX YOUR DRIVER TO USE ENDPOINT MATCHING") ? :-)
Jokes aside, something a bit less harsh such as "Matching endpoint with
device node, consider fixing driver %s to use endpoints" wouldn't be a
bad idea.
> > ---
> > 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
