On Fri, Nov 12, 2021 at 5:07 PM James Hilliard <james.hilliard1@xxxxxxxxx> wrote: > > On Fri, Nov 12, 2021 at 5:02 PM Ricardo Ribalda <ribalda@xxxxxxxxxxxx> wrote: > > > > Hi > > > > On Sat, 13 Nov 2021 at 00:59, James Hilliard <james.hilliard1@xxxxxxxxx> wrote: > > > > > > On Fri, Nov 12, 2021 at 4:50 PM Ricardo Ribalda <ribalda@xxxxxxxxxxxx> wrote: > > > > > > > > HI James > > > > > > > > You are getting -EPROTO while trying to get the current value of a > > > > control. I believe this is a hardware/firmware error. > > > > > > Hmm, any idea why v4l2-compliance passes some of the time but not > > > always? > > > > Race condition in the firmware? > > Not enough current to complete a request and end up in some kind of brown-out? > > Hmm, think that might be the way the camera might be indicating commands > are being sent too fast? Maybe a retry on the first -EPROTO seen would be > enough to fix it? Seems it was just due to the timeout being too short, this seems to fix the issue: https://lore.kernel.org/linux-media/20211114085236.2345589-1-james.hilliard1@xxxxxxxxx/ The camera now passes all v4l2-compliance tests with this change applied. > > > > > It is difficult to know without access to the hardware :) > > > > Maybe you can replicate what causes the error with just v4l-ctl calls > > and then ping the manufacturer with a simple repro. > > > > > > > > > > > > > > > > > Best regards! > > > > > > > > -- > > Ricardo Ribalda
