On Mon, Mar 20, 2017 at 05:29:07PM +0100, Philipp Zabel wrote: > According to the documentation [1], you are doing the right thing: > > The struct v4l2_subdev_frame_interval pad references a non-existing > pad, or the pad doesn’t support frame intervals. > > But v4l2_subdev_call returns -ENOIOCTLCMD if the g_frame_interval op is > not implemented at all, which is turned into -ENOTTY by video_usercopy. > > [1] https://linuxtv.org/downloads/v4l-dvb-apis/uapi/v4l/vidioc-subdev-g-frame-interval.html#return-value Thanks for confirming. > > Maybe something like the following would be a better idea? > > > > utils/media-ctl/media-ctl.c | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/utils/media-ctl/media-ctl.c b/utils/media-ctl/media-ctl.c > > index f61963a..a50a559 100644 > > --- a/utils/media-ctl/media-ctl.c > > +++ b/utils/media-ctl/media-ctl.c > > @@ -81,22 +81,22 @@ static void v4l2_subdev_print_format(struct media_entity *entity, > > struct v4l2_mbus_framefmt format; > > struct v4l2_fract interval = { 0, 0 }; > > struct v4l2_rect rect; > > - int ret; > > + int ret, err_fi; > > > > ret = v4l2_subdev_get_format(entity, &format, pad, which); > > if (ret != 0) > > return; > > > > - ret = v4l2_subdev_get_frame_interval(entity, &interval, pad); > > - if (ret != 0 && ret != -ENOTTY) > > - return; > > + err_fi = v4l2_subdev_get_frame_interval(entity, &interval, pad); > > Not supporting frame intervals doesn't warrant a visible error message, > I think -EINVAL should also be ignored above, if the spec is to be > believed. > > > > > printf("\t\t[fmt:%s/%ux%u", > > v4l2_subdev_pixelcode_to_string(format.code), > > format.width, format.height); > > > > - if (interval.numerator || interval.denominator) > > + if (err_fi == 0 && (interval.numerator || interval.denominator)) > > printf("@%u/%u", interval.numerator, interval.denominator); > > + else if (err_fi != -ENOTTY) > > + printf("@<error: %s>", strerror(-err_fi)); > > Or here. I don't mind which - I could change this to: else if (err_fi != -ENOTTY && err_fi != -EINVAL) Or an alternative would be to print an error (ignoring ENOTTY and EINVAL) to stderr at the "v4l2_subdev_get_frame_interval" callsite and continue on (ensuring that interval is zeroed). -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
