Hi Oliver, On Thursday 30 Mar 2017 10:11:31 Oliver Neukum wrote: > Am Donnerstag, den 30.03.2017, 01:15 +0300 schrieb Laurent Pinchart: > > > + may also override PAD bytes at the end of the ``transfer_buffer``, > > > up to the > > > + size of the CPU word. > > > > "May" is quite weak here. If some host controller drivers require buffers > > to be aligned, then it's an API requirement, and all buffers must be > > aligned. I'm not even sure I would mention that some host drivers require > > it, I think we should just state that the API requires buffers to be > > aligned. > > That effectively changes the API. Many network drivers are written with > the assumption that any contiguous buffer is valid. In fact you could > argue that those drivers are buggy and must use bounce buffers in those > cases. > > So we need to include the full story here. I personally don't care much about whose side is responsible for handling the alignment constraints, but I want it to be documented before "fixing" any USB driver. -- Regards, Laurent Pinchart
