Hi Kieran, On Tue, Mar 17, 2020 at 12:33:07PM +0000, Kieran Bingham wrote: > On 16/03/2020 21:47, Laurent Pinchart wrote: > > 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 > > This was the patch that I had believed was accepted, but ended up stuck > in Sakari's tree: > > https://git.linuxtv.org/sailus/media_tree.git/commit/?h=fwnode-const&id=35c32d99b2c3f5086b911ec817926de9b7bc3b41 > > (it's already a little bit-rotted though) Yes, I noticed that. I don't mind dropping this patch if you rebase yours, as long as we merge a fix :-) > >> 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 > > So if an 'old' receiver wants to use the 'new' features, it must upgrade > to endpoint matching. > > I think that's fine. Yes that's the idea. It will however not have to upgrade all the subdev drivers it uses at the same time. > >> 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") ? :-) > > Indeed, a notification that they need to update their matching would be > useful in that scenario. > > I believe we need to move forward with this somehow, as we have Xilinx > trying to use MAX9286 with Xilinx drivers, (endpoint matching subdev > with dev node matching receiver) and Renesas trying to use non-endpoint > subdevices against an endpoint matched RCar-VIN ...? > > > 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. > > Yes, Is there anything else we can do? Even if we 'started' converting > other receivers to match on endpoints, it would take time - so I think > an intermediate stage like this is still very useful. > > Of course this patch also lets us push the updates back to those who > care about those drivers too ... Exactly :-) > >>> --- > >>> 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; > > Ok, so this looks like a good safety check for edge cases which would > potentially have got through in my version. > > >>> + > >>> + /* > >>> + * 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); > > It seems in my implementation these got leaked too :-) > > I'm sold. This one is better than the old version I had. > > Hopefully we can get this moving so that we can progress towards > endpoint matching throughout next. > > (Ideally with a warning to convert non-endpoint matching drivers...) > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> Thank you. I'll add a warning and agree with Sakari on the best method to check if a node is an endpoint node, and will then resubmit. > >>> + > >>> + return dev_fwnode == other_fwnode; > >>> } > >>> > >>> static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd) -- Regards, Laurent Pinchart
