No more BLE_EVT_TX_COMPLETE in SD7

[eric ely]

I use Eclipse, gcc and OS X to compile.

I had FW working just fine with SD 6 and SDK 5.2. I recently tried to upgrade and ran into many problems, but the latest is the worst. I am now using SDK 6.1 and SD 7.0, and I also tried SD 7.1 and saw the same issue.

I have a custom service that I use to send data to an Android app. The data is usually much more than 20 bytes, so I have a loop like this in the code:

for (int i = 0; i < len; i+=20) {
	uint16_t size = (len-i > 20 ? 20 : len-i);
	memcpy(buffer, data+i, size);

	memset(&params, 0, sizeof(params));
	params.type = BLE_GATT_HVX_NOTIFICATION;
	params.handle = p_scs->data_up_handles.value_handle;
	params.p_data = buffer;
	params.p_len = &size;

	int error = sd_ble_gatts_hvx(p_scs->conn_handle, &params);

	//when sending data very fast, we can use up all the buffers. this should protect us as we wait for the TX complete event
	while (error == BLE_ERROR_NO_TX_BUFFERS) {
		simple_uart_putstring("Hit a No Buffer error \n");
		while (waitForTxComplete) {
			nrf_delay_us(500000);
			simple_uart_putstring("Still waiting \n");
		}
		waitForTxComplete = true;
		error = sd_ble_gatts_hvx(p_scs->conn_handle, &params);
		simple_uart_putstring("Still getting an error sending \n");
	}
	simple_uart_putstring("Past it \n");


	if (error != NRF_SUCCESS) {
		simple_uart_putstring("Still caught an error transmitting \n");
		if (error == BLE_ERROR_NO_TX_BUFFERS) {
			simple_uart_putstring("It's a buffer error! \n");
		}
		return error;
	}
}

Then I simply have a function in the class that listens for BLE events and does this on the event type:

   case BLE_EVT_TX_COMPLETE:
    	simple_uart_putstring("Got an event telling us we are all clear \n");
    	waitForTxComplete = false;
		break;

This all worked fine with SD6, the event would come through after the TX was complete and the data would all go through. Now, I never see the BLE_EVT_TX_COMPLETE event, and so I get stuck in a loop waiting for the TX Buffers to clear. I output debug through UART and I can see the event never comes. It transmits 7 twenty packet payloads before it hits a BLE_ERROR_NO_TX_BUFFERS error, and then it just hangs forever in the loop.

I know the events are all working properly because I send data down to the nrf51822 first and that works just fine. So it seems the only issue is the BLE_EVT_TX_COMPLETE event isn't coming through anymore. I checked documentation on the latest SD7.1 version and I cannot find anything about this.

Is there an issue? Or did something change that I am not handling correctly anymore?