Methods and apparatus for improved serial advanced technology attachment performance

A method operable in a system comprising a native Serial Advanced Technology Attachment (SATA) host coupled with a SATA target device, the method for transferring data between the SATA host and the SATA target device, the method comprising:

• receiving a DMA SETUP Frame Information Structure (FIS) in the SATA host from the SATA target device;
• and
• transmitting more than one DATA FIS to the SATA target device in response to receipt of the DMA SETUP FIS,
• wherein the SATA host does not await receipt of a DMA ACTIVATE FIS to complete the step of transmitting, and
• wherein the SATA target device does not transmit a DMA ACTIVATE FIS to complete the step of transmitting.

A method operable in a Serial Advanced Technology Attachment (SATA) storage system, the storage system comprising a storage controller and a SATA target device, the method comprising:

• transmitting a Register Frame Information Structure (FIS) comprising a command (COMMAND FIS) from the storage controller to the SATA target device wherein the COMMAND FIS is associated with data to be transmitted to the SATA target device;
• receiving in the storage controller a DMA SETUP FIS from the SATA target device in response to transmission of the COMMAND FIS;
• determining whether the DMA SETUP FIS includes an indicator requesting AUTO-ACTIVATE;
• responsive to a determination that the DMA SETUP FIS does not include an AUTO-ACTIVATE indicator, awaiting receipt of a first DMA ACTIVATE FIS from the SATA target device;
• responsive to receipt of the first DMA ACTIVATE FIS and/or responsive to a determination that the DMA SETUP FIS includes an AUTO-ACTIVATE indicator, performing the steps of:
• transmitting a DATA FIS from the storage controller to the SATA target device using a direct memory access (DMA) circuit of the storage controller wherein the DATA FIS comprises a portion of the data associated with the COMMAND FIS and wherein the step of transmitting the DATA FIS further comprises:
• detecting receipt of a DMA ACTIVATE FIS from the SATA target device;
• and
• discarding the DMA ACTIVATE FIS responsive to detection of receipt of the DMA ACTIVATE FIS;
• and
• repeating the step of transmitting a DATA FIS until all data associated with the COMMAND FIS is transmitted to the SATA target device.

A Serial Attached SCSI (SAS) expander comprising:

• a first interface adapted to couple the expander with a Serial Attached SCSI Serial Advanced Technology Attachment Tunneling Protocol (SAS/STP) initiator;
• a second interface adapted to couple the expander with a SATA target device;
• and
• bridge logic adapted to transfer data received from the SAS/STP initiator through the first interface to the SATA target device through the second interface, wherein the data is associated with a Register Frame Information Structure comprising a command (COMMAND FIS),
• wherein the bridge logic is further adapted to discard any DMA ACTIVATE FIS received from the SATA target device through the second interface until transfer of the data associated with the COMMAND FIS is completed.

A storage system comprising:

• a Serial Advanced Technology Attachment (SATA) host;
• and
• a SATA storage device coupled with the SATA host,
• wherein the SATA host is adapted to transfer data to the storage device without requiring a DMA ACTIVATE Frame Information Structure (FIS) after transmission of each of a plurality of DATA FISs.