>>>>> "Alan" == Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> writes: I'm guessing Doug is out today because he didn't forward the note below. Just passing the info along... >> It is needed by the transport protocol(s). Alan> I don't understand; can you explain more fully? Which transport Alan> protocol(s) need to use the Sector Count? The USB transport Alan> protocol doesn't; it encodes the transfer length in a wrapper. Alan> The bridge chip should interpret the wrapper instead of looking Alan> inside the SAT command. Doug posted to the T10 list and here's what Jim Hatfield from Seagate responded: For ATA (SATA or PATA), the Count field should NEVER be zero, because neither interface supports zero-length data transfer for any protocol (dma, pio, etc). In ATA, 'N/A' is defined the way it is because there are some ancient implementations for which there are vendor specific differences. -- Martin K. Petersen Oracle Linux Engineering -- 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