Hi Andrey, On Thu, Feb 18, 2021 at 01:11:32AM +0300, Andrey Konovalov wrote: > Print a warning if V4L2_CID_LINK_FREQ control is not implemented. > > Signed-off-by: Andrey Konovalov <andrey.konovalov@xxxxxxxxxx> > --- > drivers/media/v4l2-core/v4l2-common.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c > index 133d20e40f82..f1abdf2ab4ec 100644 > --- a/drivers/media/v4l2-core/v4l2-common.c > +++ b/drivers/media/v4l2-core/v4l2-common.c > @@ -461,6 +461,8 @@ s64 v4l2_get_link_freq(struct v4l2_ctrl_handler *handler, unsigned int mul, > > freq = qm.value; > } else { > + pr_warn("%s: V4L2_CID_LINK_FREQ not implemented\n", __func__); > + It's a shame we can't access a struct device * somehow :( Also, nitpicking (please bear with me here) it is absolutely correct that V4L2_CID_LINK_FREQ is not implemented, but I think the real deal here is that the link rate is estimanted from PIXEL_RATE and that might be wrong. What about (insipired from the error message in match_fwnode() which I find useful) pr_warn("%s: Link frequency estimanted using pixel rate: result might be inaccurate\n", __func__); pr_warn("%s: Consider implementing support for V4L2_CID_LINK_FREQ in the transmitter driver\n", __func___); Anyway, whatever works Reviewed-by: Jacopo Mondi <jacopo@xxxxxxxxxx> Thanks j > if (!mul || !div) > return -ENOENT; > > -- > 2.17.1 >