On 03/06/2014 02:45 AM, Laurent Pinchart wrote: > Hi Hans, > > Thank you for the patches. > > On Tuesday 04 March 2014 12:30:55 Hans Verkuil wrote: >> Currently the VIDIOC_SUBDEV_G/S_EDID and struct v4l2_subdev_edid are subdev >> APIs. However, that's in reality quite annoying since for simple video >> pipelines there is no need to create v4l-subdev device nodes for anything >> else except for setting or getting EDIDs. >> >> What happens in practice is that v4l2 bridge drivers add explicit support >> for VIDIOC_SUBDEV_G/S_EDID themselves, just to avoid having to create >> subdev device nodes just for this. >> >> So this patch series makes the ioctls available as regular ioctls as >> well. In that case the pad field should be set to 0 and the bridge driver >> will fill in the right pad value internally depending on the current >> input or output and pass it along to the actual subdev driver. > > Would it make sense to allow usage of the pad field on video nodes as well ? No, really not. The video node driver has full control over which inputs/outputs map to which pads. None of that is (or should be) visible from userspace. What should probably change is that rather than requiring userspace to set pad to 0, I just say that it is ignored. The bridge driver will fill in the pad before handing it over to the relevant subdev. Requiring apps to set it to 0 (which is a valid pad number anyway, so that doesn't really help with possible future use of the field) will require the driver to set it to 0 as well after having called the subdev. Which is annoying and will be forgotten anyway. I also need to mention in the docbook that if it is called for a pad, an input or an output that does not support EDIDs these ioctls will return -EINVAL. I'll post a REVIEWv1 series soon. Regards, Hans > > Apart from that and minor issues with patch 2/4 this series looks good to me. > -- 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
