Em Wed, 06 May 2015 12:50:31 +0200 Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: > On 05/06/15 11:30, Mauro Carvalho Chehab wrote: > > Em Wed, 06 May 2015 08:57:15 +0200 > > Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: > > > >> From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > >> > >> This patch series adds the VIDIOC_SUBDEV_QUERYCAP ioctl for v4l-subdev devices > >> as discussed during the ELC in San Jose and as discussed here: > >> > >> http://www.spinics.net/lists/linux-media/msg88009.html > >> > >> It also add support for MEDIA_IOC_DEVICE_INFO to any media entities so > >> applications can use that to find the media controller and detailed information > >> about the entity. > > > > Why "IOC" at MEDIA_IOC_DEVICE_INFO? > > Probably based on 'VIDIOC'. I can't help that that's the ioctl name. > The MEDIA_IOC_DEVICE_INFO ioctl already exists as part of the media > API. So I am not making a new ioctl here. Ah, ok. > > > > Also, I'm not sure yet how do you think apps should use this information, > > especially when multiple media controller entities are present. > > > > IMHO, the media controller instance number should be added at the > > struct. Also, IMO, the docbook would need to give an usage example > > for this ioctl. > > The major+minor identifies the media controller exactly. An instance > number doesn't add anything, or am I missing something? Ah, so the major+minor are for the media controller device node, and not for the v4l2 devnode. OK. > > And yes, a usage example will be needed, but this is still an RFC. > > >> > >> This is the second RFC patch series. The main changes are: > >> > >> - Drop the entity ID from the querycap ioctls > > > > I'm not seeing this happening. Also, removing something at existing > > ioctls may break userspace. > > Changes since the *previous RFC patch series*. The existing code doesn't > have an entity_id. ah, ok. I guess I should avoid avoid answering emails very early at morning without taking first a good cup of coffee ;) > > Regards, > > Hans > > >> - Instead have every entity device implement MEDIA_IOC_DEVICE_INFO > >> - Add major, minor and entity_id fields to struct media_device_info: > >> this allows applications to find the MC device and to determine > >> the entity ID of the device for which they called the ioctl. It > >> is 0 for the MC (entity IDs are always > 0 for entities). > >> > >> This is IMHO simple, consistent, and it will work for any media entity. > >> > >> Regards, > >> > >> Hans > >> > >> PS: I have not tested the DVB changes yet. I hope I got those right. > >> > >> Hans Verkuil (8): > >> v4l2-subdev: add VIDIOC_SUBDEV_QUERYCAP ioctl > >> DocBook/media: document VIDIOC_SUBDEV_QUERYCAP > >> videodev2.h: add V4L2_CAP_ENTITY to querycap > >> media: add major/minor/entity_id to struct media_device_info > >> v4l2-subdev: add MEDIA_IOC_DEVICE_INFO > >> v4l2-ioctl: add MEDIA_IOC_DEVICE_INFO > >> dvb: add MEDIA_IOC_DEVICE_INFO > >> DocBook/media: document the new media_device_info fields. > >> > >> .../DocBook/media/v4l/media-ioc-device-info.xml | 35 +++++- > >> Documentation/DocBook/media/v4l/v4l2.xml | 1 + > >> .../DocBook/media/v4l/vidioc-querycap.xml | 6 + > >> .../DocBook/media/v4l/vidioc-subdev-querycap.xml | 125 +++++++++++++++++++++ > >> drivers/media/dvb-core/dmxdev.c | 24 +++- > >> drivers/media/dvb-core/dvb_ca_en50221.c | 11 ++ > >> drivers/media/dvb-core/dvb_net.c | 11 ++ > >> drivers/media/media-device.c | 29 +++-- > >> drivers/media/media-devnode.c | 5 +- > >> drivers/media/v4l2-core/v4l2-ioctl.c | 43 ++++++- > >> drivers/media/v4l2-core/v4l2-subdev.c | 26 +++++ > >> include/media/media-device.h | 3 + > >> include/media/media-devnode.h | 1 + > >> include/uapi/linux/media.h | 5 +- > >> include/uapi/linux/v4l2-subdev.h | 10 ++ > >> include/uapi/linux/videodev2.h | 1 + > >> 16 files changed, 316 insertions(+), 20 deletions(-) > >> create mode 100644 Documentation/DocBook/media/v4l/vidioc-subdev-querycap.xml > >> > > -- > > 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 > > > -- 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
