Hi Kieran, On Wed, Mar 18, 2020 at 09:22:21AM +0000, Kieran Bingham wrote: > On 18/03/2020 00:25, Laurent Pinchart wrote: > > Use the presence of a "remote-endpoint" property to detect if a fwnode > > is an endpoint node, as checking the node name won't work on ACPI-based > > implementations. > > Technically, won't this property only detect that the endpoint is > connected to another endpoint, and 'un-connected' endpoints wont' match? > > Of course in this instance - an unconnected endpoint is likely not much > use and probably even shouldn't match ;-) ~(but it may still 'be' an > endpoint). Yes, technically speaking, this detects whether the node is an endpoint and is connected. As you mentioned, there's little use in unconnected endpoints here, as nobody would attempt to match them. > Also - would this patch be squashed into 1/4? I think that would make sense, yes. I'll do so in v3. > I'll leave it to Sakari to comment on the actual validity of this > approach all the same :-) ACPI has a remote-endpoint property, but has no endpoint nodes. I wonder what the remote-endpoint points to... > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > > --- > > drivers/media/v4l2-core/v4l2-async.c | 9 ++++----- > > 1 file changed, 4 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c > > index 9f393a7be455..a5f83ba502df 100644 > > --- a/drivers/media/v4l2-core/v4l2-async.c > > +++ b/drivers/media/v4l2-core/v4l2-async.c > > @@ -78,7 +78,6 @@ static bool match_fwnode(struct v4l2_async_notifier *notifier, > > bool asd_fwnode_is_ep; > > bool sd_fwnode_is_ep; > > struct device *dev; > > - const char *name; > > > > /* > > * Both the subdev and the async subdev can provide either an endpoint > > @@ -92,10 +91,10 @@ static bool match_fwnode(struct v4l2_async_notifier *notifier, > > * 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"); > > + sd_fwnode_is_ep = fwnode_property_present(sd->fwnode, > > + "remote-endpoint"); > > + asd_fwnode_is_ep = fwnode_property_present(asd->match.fwnode, > > + "remote-endpoint"); > > > > if (sd_fwnode_is_ep == asd_fwnode_is_ep) > > return false; -- Regards, Laurent Pinchart
