Xiaoguang Wu 640d896508 DM USB: change TRB ring processing logic for ISOC transfer ...

Current ring buffer processing logic assumes every transaction
will be submited to physical device before next transaction
coming. So it use two states 0 (free) and 1 (used) to represent
the state of every data block in the ring buffer. With the help
of the two state, the ring buffer could accept and process data
normally.

But this logic is not proper for ISOC transfer, which generally
submits many transactions even none of them arrive the physical
device. So this patch uses three values to represent the state
of data block in the ring buffer:
USB_XFER_BLK_FREE: this block could be filled with new data;
USB_XFER_BLK_HANDLING: this block is submited to physical device
but response from device is still not received;
USB_XFER_BLK_HANDLED: this block has been processed by physical
device.

The new logic will do different things for each state, which will
make the ISOC transfer work successfully.

Change-Id: I5559cae24c739633289742d64dd51751797b81a7
Tracked-On:
Signed-off-by: Xiaoguang Wu <xiaoguang.wu@intel.com>
Reviewed-by: Liang Yang <liang3.yang@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

2018-07-20 10:42:34 +08:00

19 KiB

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