On 01-03-21, 16:46, Arnd Bergmann wrote: > But the driver does not support this at all: the sglist always has three > members as Viresh says: outhdr, msgbuf and inhdr. It then uses a > bounce buffer for the actual data transfer, and this always goes either > one way or the other. Yes and if the driver doesn't support the specification fully then it should say so in a comment at least and also fail in case someone tries a full duplex transfer.. -- viresh