- Don't compare the DMA map to NULL to determine if bus_dmamap_unload()
should be called when releasing a static allocation. Instead, compare
the bus address against 0.
- Don't assume that the DMA map for static allocations is NULL. Instead,
save the value set by bus_dmamem_alloc() so it can later be passed to
bus_dmamem_free(). Also, add missing calls to bus_dmamap_unload() in
these cases before freeing the buffer.
- Use the bus address from the bus_dma callback instead of calling
vtophys() on the address allocated by bus_dmamem_alloc().
Reviewed by: kan
46e105f753