Hi Thinh, > On Wed, Oct 19, 2022 at 11:06:08PM +0000, Thinh Nguyen wrote: > > Hi, > > <snip> > > > > > > > The logic to detect underrun doesn't trigger because the queued list is > > > > always non-empty, but the queued requests are expected to be missed > > > > already. So you keep seeing missed isoc. > > > > > > > > There are a few things you can mitigate this issue: > > > > 1) Don't set IMI if the request indicates no_interrupt. This reduces the > > > > time software needs to handle interrupts. > > > > > > > > > > 2) Improve the underrun detection logic. > > > > > > > > > > 3) Increase the queuing frequency from the uvc to keep the request queue > > > > full. Note that reduce/avoid setting no_interrupt will allow the > > > > controller driver to update uvc often to keep requeuing new requests. > > > > > > > > Best option is 3), but maybe we can do all 3. > > > > > > > I forgot about your option 2. Will start looking into it. Thanks, Jeff