On Mo, 2019-04-29 at 13:31 +0000, David Laight wrote: > From: Oliver Neukum > > > > + * USB has unusual scatter-gather requirements: the length of each > > + * scatterlist element except the last must be divisible by the > > + * Bulk maxpacket value. Fortunately this value is always a > > + * power of 2. Inform the block layer about this requirement. > > + */ > > That isn't the correct restriction for XHCI. > It has its own perverse restrictions. > I think they are all handled within the xhci driver. Yes, but that does not matter. You just cannot assume that only XHCI will be used with UAS. In particular virtual drivers will be used. Regards Oliver