On Thu, Sep 20, 2018 at 09:28:37AM +0800, Ming Lei wrote: > > has e.g. PAGE_SIZE alignment requirement (this would likely imply that > > it's sector size is also not 512 I guess)? > > Yeah, that can be true if one controller has 4k-byte sector size, also > its DMA alignment is 4K. But there shouldn't be cases in which the two > doesn't match. The general block storage worlds is that devices always need to have an alignment requirement <= minimum LBAs size. If they don't they'll need to bounce buffer (in the driver!).