Mark Kettenis wrote: > OpenBSD/arm seems to be the only port that doesn't like it when you > pass its bus_dmamap_sync() a size of zero. While it is indeed a bit > silly to do so, adding checks for this in the drivers might be > overkill. In fact if you read the bus_dma_sync(9) man page, you could > could interpret from > > On platforms which implement reordered stores, bus_dmamap_sync() will > always cause the store buffer to be flushed. > > that passing a size of zero is useful to flush the store buffers. > > So my idea is that we simply remove the check.
In many other contexts, zero lengths are acceptable. (even so when other arguments are not). makes a lot of sense to me.
