On Tue, Aug 20, 2013 at 1:08 PM, Nicholas A. Bellinger <nab@xxxxxxxxxxxxx> wrote: > Add a special case for COMPARE_AND_WRITE for the reverse data direction > mapping used for pci_map_sg() + friends. I don't understand this. In fact the whole patch series looks quite confused. COMPARE AND WRITE is a normal Data-Out command, with no requirement for special bidirectional handling or anything like that. The only slightly unusual thing is that a CAW command with a NUMBER OF LOGICAL BLOCKS equal to N will actually transfer 2*N worth of data -- one set of data for the compare operation and a second set to write if the compare succeeds. But just to be clear, the transfer of those 2*N blocks happens as a single transfer during the Data-Out phase. - R. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
