On 04.06.22 18:40, Alan Stern wrote: > > I don't see anything wrong with this, except that it would be nice to keep > the flag values in numerical order. In other words, set URB_FREE_COHERENT > to 0x0200 and change URB_DIR_IN to 0x0400. Hi, but what sense does this patch make? You use coherent allocations to avoid repeated DMA synchronizations. That is sort of incompatible with the notion of discarding the buffer automatically. Regards Oliver