On Mon, Dec 20, 2021 at 10:11:30PM +0100, Pavel Hofman wrote: > So far bInterval for HS and SS was fixed at 4, disallowing faster > samplerates. The patch determines the largest bInterval (4 to 1) for > which the required bandwidth of the max samplerate fits the max allowed > packet size. If the required bandwidth exceeds max bandwidth for > single-packet mode (ep->mc=1), bInterval is left at 1. I'm not sure if this is desirable - there are more concerns around the interval than just whether the bandwidth is available. The nice thing about having the HS/SS interval at 4 when the FS value is 1 is that these both correspond to 1ms, which means the calculations for minimum buffer & period sizes are the same for FS/HS/SS. How do FS transfers work if the bandwidth requirements necessitate a smaller interval for HS/SS? Doesn't that mean the FS transfers must be too big? I don't think there has ever been a check that the configured sample size, channel count and interval actually fit in the max packet size for an endpoint. Is that something that should be checked to give an error on bind if the configuration can't work? > The FS mode is left at fixed bInterval=1. > > Signed-off-by: Pavel Hofman <pavel.hofman@xxxxxxxxxxx>
