On Thursday 03 October 2013 11:43:01 Sakari Ailus wrote: > On Thu, Oct 03, 2013 at 11:16:59AM +0900, Sylwester Nawrocki wrote: > > On 10/03/2013 08:29 AM, Laurent Pinchart wrote: > > > On Thursday 03 October 2013 02:17:50 Sakari Ailus wrote: > > >> Pads that set this flag must be connected by an active link for the > > >> entity to stream. > > >> > > >> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx> > > >> Acked-by: Sylwester Nawrocki <sylvester.nawrocki@xxxxxxxxx> > > > > > > Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > > > Looks good, I would just like to ask for changing my e-mail address on > > those patches to s.nawrocki@xxxxxxxxxxx, sorry for not mentioning it > > earlier. Just one doubt below regarding name of the flag. > > Will do. > > > >> --- > > >> > > >> Documentation/DocBook/media/v4l/media-ioc-enum-links.xml | 10 ++++++ > > >> include/uapi/linux/media.h | 1 + > > >> 2 files changed, 11 insertions(+) > > >> > > >> diff --git a/Documentation/DocBook/media/v4l/media-ioc-enum-links.xml > > >> b/Documentation/DocBook/media/v4l/media-ioc-enum-links.xml index > > >> 355df43..e357dc9 100644 > > >> --- a/Documentation/DocBook/media/v4l/media-ioc-enum-links.xml > > >> +++ b/Documentation/DocBook/media/v4l/media-ioc-enum-links.xml > > >> @@ -134,6 +134,16 @@ > > >> <entry>Output pad, relative to the entity. Output pads source > > >> data and are origins of links.</entry> > > >> </row> > > >> + <row> > > >> + <entry><constant>MEDIA_PAD_FL_MUST_CONNECT</constant></entry> > > >> + <entry>If this flag is set and the pad is linked to any other > > >> + pad, then at least one of those links must be enabled for the > > >> + entity to be able to stream. There could be temporary reasons > > >> + (e.g. device configuration dependent) for the pad to need > > >> + enabled links even when this flag isn't set; the absence of the > > >> + flag doesn't imply there is none. The flag has no effect on pads > > >> + without connected links.</entry> > > > > Probably MEDIA_PAD_FL_MUST_CONNECT name is fine, but isn't it more > > something like MEDIA_PAD_FL_NEED_ACTIVE_LINK ? Or presumably > > MEDIA_PAD_FL_MUST_CONNECT just doesn't make sense on pads without > > connected links and should never be set on such pads ? From the last > > sentence it feels the situation where a pad without a connected link has > > this flags set is allowed and a valid configuration. If I'm not mistaken, that's a valid configuration. The flag merely says that, if a pad has any link, then one of them must be active (Sakari, please correct me if I'm wrong). > > Perhaps the last sentence should be something like: > > > > "The flag should not be used on pads without connected links and has no > > effect on such pads." > > Hmm. Good question. My assumption was that such cases might appear when an > external entity could be connected to the pad, but receivers typically have > just a single pad. So streaming would be out of question in such case > anyway. But my thought was that we shouldn't burden drivers by forcing them > to unset the flag if there happens to be nothing connected to an entity. > > How about just that I remove the last sentence, and s/ and the pad is linked > to any other pad, then at least one of those links must be enabled/, the > pad must be connected by an enabled link/? :-) > > The purpose is two-fold: to allow automated pipeline validation and also > hint the user what are the conditions for that configuration. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
