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. > > 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? 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. 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
