Command draining using host memory buffer
The present disclosure generally relates to aborting a command efficiently using the host memory buffer (HMB). The command contains pointers that direct the data storage device to various locations on the data storage device where relevant content is located. Once the abort command is received, the content of the host pointers stored in the data storage device RAM are changed to point to the HMB. The data storage device then waits until any already started transactions over the interface bus that are associated with the command have been completed. Thereafter, a failure completion command is posted to the host device.
1. A data storage device, comprising:
one or more memory devices; and
a controller coupled to the one or more memory devices, wherein the controller is configured to:
receive an original command from a host device;
determine to complete original command with Advanced Command Retry (ACR);
allocate one or more buffers within host memory buffers (HMBs) for holding a set of data associated with the original command;
return a completion message with an ACR indication to the host device, wherein the completion message requests the host device to re-try the original command;
execute the original command while transferring data to the allocated one or more buffers within HMBs;
receive a reissued original command from the host device; and
copy data for the reissued original command from the allocated one or more buffers within HMBs.
2. The data storage device of claim 1 , wherein when the controller returns the completion message to the host device:
a representation of the data is issued on an interface of the host device; and
the data stored in the HMBs, wherein the HMBs are not used for draining data, and wherein the HMBs comprise a plurality of buffers in sufficient size to maintain data to ensure the data storage device can copy data from the HMB to the host device upon receiving a command from the host device to retrieve the data.
3. The data storage device of claim 1 , wherein the controller is further configured to:
receive a re-issue command of the original command from the host device.
4. The data storage device of claim 3 , wherein the controller is further configured to copy data from the one or more HMBs.
5. The data storage device of claim 4 , wherein the copying comprises copying the data from the one or more HMBs to a host buffer for the re-issued command.
6. The data storage device of claim 1 , wherein the controller is configured to wait for completing current transfers associated with the original command that have already started prior to returning the completion message, wherein after the controller returns the completion message the data storage device does not access original buffers with original command, and wherein after the controller returns the completion message the data storage device can access the one or more HMBs.
7. The data storage device of claim 6 , wherein during the waiting and prior to returning the completion message, the data storage device may access the original buffers and the one or more HMBs in parallel.