Shared buffer for data communications routed through hub
Various techniques are provided for selectively allocating a buffer adapted to be shared for storage media device data communications and downstream device data communications routed through a hub. For example, in one embodiment, a method includes detecting if one or more downstream devices are connected to one or more downstream device ports of the hub. The method also includes, if any downstream devices are detected: allocating a first portion of the buffer for a storage media device controller, allocating one or more second portions of the buffer for the detected downstream devices, wherein each of the second portions is associated with a corresponding one of the detected downstream devices, and passing the storage media device data communications between a host device and the storage media device controller through the first portion of the buffer and not the second portions of the buffer.
1. A method of selectively allocating a buffer adapted to be shared for storage media device data communications and downstream device data communications routed through a hub, the method comprising:
detecting if one or more downstream devices are connected to one or more downstream device ports of the hub; and
if any downstream devices are detected:
allocating a first portion of the buffer for a storage media device controller,
allocating one or more second portions of the buffer for the detected downstream devices, wherein each of the second portions is associated with a corresponding one of the detected downstream devices, and
passing the storage media device data communications between a host device and the storage media device controller through the first portion of the buffer and not the second portions of the buffer.
2. The method of claim 1 , further comprising passing the downstream device data communications between the host device and the detected downstream devices through the second portions of the buffer and not the first portion of the buffer.
3. The method of claim 2 , wherein the first portion of the buffer and at least one of the second portions of the buffer overlap with each other, the method further comprising switching between:
using the first portion of the buffer to pass the storage media device data communications; and
using the at least one of the second portions of the buffer to pass the downstream device data communications.
4. The method of claim 2 , further comprising:
populating a route table with device identifiers associated with the detected downstream devices; and
routing the downstream device data communications using the route table.
5. The method of claim 1 , further comprising:
if no downstream devices are detected:
allocating a third portion of the buffer comprising substantially all of the buffer for the storage media device controller; and
passing the storage media device data communications between the host device and the storage media device controller through the third portion of the buffer.
6. The method of claim 1 , further comprising:
receiving a Universal Serial Bus (USB) enumeration request from the host device; and
delaying providing a response to the USB enumeration request to register the storage media device controller with the host device until at least after the buffer has been allocated.
7. The method of claim 1 , wherein the downstream device ports are Universal Serial Bus (USB) 3.0 ports and the detected downstream devices are USB 3.0 devices.
8. The method of claim 1 , wherein the hub further comprises a plurality of storage media device ports adapted to interface one or more storage media devices with the storage media device controller.
9. The method of claim 8 , wherein the hub is implemented in a storage media device enclosure and at least one of the storage media device ports is adapted to be connected to a storage media device in the storage media device enclosure.
10. The method of claim 8 , wherein the storage media device ports are Serial Advanced Technology Attachment (SATA) ports.
11. The method of claim 8 , wherein the storage media device ports are flash memory interface ports.
12. The method of claim 8 , further comprising operating the storage media devices such that the host device perceives the storage media devices as a single storage media device.
13. The method of claim 8 , further comprising transferring data between the storage media devices without intervention by the host device.
14. The method of claim 8 , further comprising operating at least a first one of the storage media devices as a cache for at least a second one of the storage media devices.
15. The method of claim 1 , wherein the storage media device controller is integrated with the hub.
16. A device comprising:
a host device port adapted to interface with a host device;
one or more downstream device ports adapted to interface with one or more downstream devices;
a storage media device controller;
a hub; and
a buffer adapted to be shared for storage media device data communications and downstream device data communications routed through the hub, wherein the hub is adapted to:
detect if one or more downstream devices are connected to the one or more downstream device ports, and
if any downstream devices are detected, allocate a first portion of the buffer for the storage media device controller, allocate one or more second portions of the buffer for the detected downstream devices, wherein each of the second portions is associated with a corresponding one of the detected downstream devices, and pass the storage media device data communications between the host device and the storage media device controller through the first portion of the buffer and not the second portions of the buffer.
17. The device of claim 16 , wherein the hub is further adapted to pass the downstream device data communications between the host device and the detected downstream devices through the second portions of the buffer and not the first portion of the buffer.
18. The device of claim 17 , wherein the first portion of the buffer and at least one of the second portions of the buffer overlap with each other, and wherein the hub is further adapted to switch between:
using the first portion of the buffer to pass the storage media device data communications; and
using the at least one of the second portions of the buffer to pass the downstream device data communications.
19. The device of claim 17 , wherein:
the hub comprises a route table adapted to store device identifiers associated with the detected downstream devices; and
the hub is adapted to populate the route table with the device identifiers and route the downstream device data communications using the route table.
20. The device of claim 16 , wherein the hub is further adapted to, if no downstream devices are detected:
allocate a third portion of the buffer comprising substantially all of the buffer for the storage media device controller; and
pass the storage media device data communications between the host device and the storage media device controller through the third portion of the buffer.
21. The device of claim 16 , wherein the hub is further adapted to:
receive a Universal Serial Bus (USB) enumeration request from the host device; and
delay a response to the USB enumeration request to register the storage media device controller with the host device until at least after the buffer has been allocated.
22. The device of claim 16 , wherein the downstream device ports are Universal Serial Bus (USB) 3.0 ports and the detected downstream devices are USB 3.0 devices.
23. The device of claim 16 , wherein the device further comprises a plurality of storage media device ports adapted to interface one or more storage media devices with the storage media device controller.
24. The device of claim 23 , wherein the device is a storage media device enclosure and at least one of the storage media device ports is adapted to be connected to a storage media device in the storage media device enclosure.
25. The device of claim 23 , wherein the storage media device ports are Serial Advanced Technology Attachment (SATA) ports.
26. The device of claim 23 , wherein the storage media device ports are flash memory interface ports.
27. The device of claim 23 , wherein the device is adapted to operate the storage media devices such that the host device perceives the storage media devices as a single storage media device.
28. The device of claim 23 , wherein the device is adapted to transfer data between the storage media devices without intervention by the host device.
29. The device of claim 23 , wherein the device is adapted to operate at least a first one of the storage media devices as a cache for at least a second one of the storage media devices.
30. The device of claim 16 , wherein the storage media device controller is integrated with the hub.
31. A device comprising:
a host device port adapted to interface with a host device;
one or more downstream device ports adapted to interface with one or more downstream devices;
a storage media device controller;
a buffer adapted to be shared for storage media device data communications and downstream device data communications;
means for detecting if one or more downstream devices are connected to the one or more downstream device ports;
means for allocating a first portion of the buffer for the storage media device controller;
means for allocating one or more second portions of the buffer for the detected downstream devices, wherein each of the second portions is associated with a corresponding one of the detected downstream devices, and
means for passing the storage media device data communications between a host device and the storage media device controller through the first portion of the buffer and not the second portions of the buffer.