Atsushi Nemoto wrote:
But the "Command Transfer Mode Select" bits affects access timings on setting task registers for DMA command.
So what? PIO and DMA are different protocols on IDE bus, so they shouldn't affect each other. The IDE core will always tune the best PIO mode for you, so the optimal command timings will be set.
Hmm, that would be a thing I had misunderstood. I thought set_pio_mode is not called when the drive was DMA capable.
PIO autotuning was optional before (done only if the driver requested it via setting drive->autotune), but now done always.
MBR, Sergei