Active scan throughput is poor on nRF5340 using nRF BLE Controller.

[loquat]

I try to run samples/bluetooth/scan_adv on nRF52840/nRF5340 using nRF BLE Controller..

Result is
nRF52840/active scan:  498 packet/s
nRF52840/passive scan:  507 packet/s

nRF5340(NetCore)/active scan: 69 packet/s
nRF5340(NetCore)/passive scan: 421 packet/s

Why nRF5340(NetCore)/active scan is poor?

sample source

/* main.c - Application main entry point */

/*
 * Copyright (c) 2015-2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/types.h>
#include <stddef.h>
#include <sys/printk.h>
#include <sys/util.h>

#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>

static u8_t mfg_data[] = { 0xff, 0xff, 0x00 };

static const struct bt_data ad[] = {
	BT_DATA(BT_DATA_MANUFACTURER_DATA, mfg_data, 3),
};

volatile uint32_t s_recv_count;

static void scan_cb(const bt_addr_le_t *addr, s8_t rssi, u8_t adv_type,
		    struct net_buf_simple *buf)
{
	mfg_data[2]++;
	s_recv_count++;
}

void main(void)
{
	struct bt_le_scan_param scan_param = {
		.type		= BT_HCI_LE_SCAN_ACTIVE,
//		.type       = BT_HCI_LE_SCAN_PASSIVE,
		.filter_dup = BT_HCI_LE_SCAN_FILTER_DUP_DISABLE,
		.interval   = 0x0010,
		.window     = 0x0010,
	};
	int err;

	printk("Starting Scanner/Advertiser Demo\n");

	/* Initialize the Bluetooth Subsystem */
	err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return;
	}

	printk("Bluetooth initialized\n");

	err = bt_le_scan_start(&scan_param, scan_cb);
	if (err) {
		printk("Starting scanning failed (err %d)\n", err);
		return;
	}

	do {
		k_sleep(K_MSEC(400));

#if 0
		/* Start advertising */
		err = bt_le_adv_start(BT_LE_ADV_NCONN, ad, ARRAY_SIZE(ad),
				      NULL, 0);
		if (err) {
			printk("Advertising failed to start (err %d)\n", err);
			return;
		}

		k_sleep(K_MSEC(400));

		err = bt_le_adv_stop();
		if (err) {
			printk("Advertising failed to stop (err %d)\n", err);
			return;
		}
#endif
	} while (1);
}

[Jørgen Holmefjord]

Hi,

Do I understand you correctly, that you run the unmodified code from samples/bluetooth/scan_adv on both the nRF52840 board and the nRF5340 application core?

Do you run the Bluetooth: HCI RPMsg sample on the nRF5340 network core?

If you can confirm my questions, I can try to reproduce the behavior on my boards.

Best regards,
Jørgen

[loquat]

changes follow,
1. add scan_cb() callback number count.
2. scan_param's type change from BT_HCI_LE_SCAN_PASSIVE to BT_HCI_LE_SCAN_ACTIVE.
3. advertising operation disable.
4. use nRF BLE Controller(not zephyr BLE HCI stack)

> Do you run the Bluetooth: HCI RPMsg sample on the nRF5340 network core?
No,
I run nRF5340 network core only.(scan_adv build target is nrf5340_dk_nrf5340_cpunet)

for check callback number count, I use SEGGER J-link debugger(Ozone)

[Sigurd]

Hi,

I will try to reproduce the behavior here.

I assume you are on fw-nrfconnect-nrf master? what is the latest commit on the master you are using ?

How does the prj.conf file you are using look like ?

[Sigurd]

Hi loquat,

We have now observed the same behavior as you did, and we are investigating the issue. I will keep you informed about what we find.

[loquat]

I checkout fw-nrfconnect-nrf(master SHA-1: 2a63123c5c68d1b3f6668d47c0a5d8ad2fcc665d)
And rebuild scan_adv.
Result is same. (nRF5340 active scan is poor.)

There are strange things.

If there are only about 100 advertises per seconds in the space, about 90 advertises be received for both active and passive.
However, if there is about 1000 advertises per seconds in the space, be received about 500 advertises on passives and about 60 advertises on actives will be received.

[Sigurd]

Hi loquat,

We have found and fixed the issue. We will release a new version of the ble_controller with the fix soon(most likely sometime next week). 

[loquat]

OK.Thanks.

I hope you.