We are hearing artifacts when listening to HFP call audio. We did some debugging and found that the CC2564C corrupts the first 2 bytes of some packets that it sends to the host. I've attached CC2564C firmware, over the air, and HCI BTSnoop logs. Following are 2 examples of failures from those logs:
1. Frame 250 in the air log contains the data for frame 494 in the HCI log
- Over the air the first 2 bytes of the eSCO payload are b6 66
- In HCI the first 2 bytes of the eSCO payload are 72 67
- The remaining 58 bytes are correct
2. Frame 3,676 in the air log contains the data for frame 5,572 in the HCI log
- Over the air the first 2 bytes of the eSCO payload are dc 37
- In HCI the first 2 bytes of the eSCO payload are 18 da
- The remaining 58 bytes are correct
It seems that every time I see corrupted audio, the packet was retransmitted by the remote device, surely it's not a coincidence. In these logs the following hardware and software were used:
- TI device: CC2564C, SP 1.1, Bluetopia stack, our app layer
- Remote device: Windows 10, Intel built-in Bluetooth adapter on a Lenovo laptop
