Williams, Dan J wrote: > In preparation for adding more operation types to the ioat3 path the > driver needs to honor the DMA_PREP_FENCE flag. For example the async_tx api > will hand xor->memcpy->xor chains to the driver with the 'fence' flag set on > the first xor and the memcpy operation. This flag in turn sets the 'fence' > flag in the descriptor control field telling the hardware that future > descriptors in the chain depend on the result of the current descriptor, so > wait for all writes to complete before starting the next operation. > > Note that ioat1 does not prefetch the descriptor chain, so does not > require/support fenced operations. > > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> > --- Signed-off-by: Maciej Sosnowski <maciej.sosnowski@xxxxxxxxx>-- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
