The IL memory is unavailable when the processor goes to sleep, causing
any involved DMA transfer to stall. The dma_transfer_wait() normally
sleeps to save battery power, but this causes the whole system to freeze
and never wake up.
This change lets dma_transfer_wait() decide dynamically whether to sleep
or spinlock. There is no concrete improvement over dma_transfer_noint()
when using IL memory, but it makes dma_transfer() fully generic.
Obviously the same goes for X and Y memory.
Lephe
bb77e4588d
