Zephyr controller unable to discover characteristics after a while

RE: Zephyr controller unable to discover characteristics after a while

vich — Tue, 12 Sep 2017 08:58:16 GMT

I see the uploaded btsnoop with mynewt controller. The host seems not to be Bluez, as it does not do the HCI sequeunces that BlueZ is known to perform. I dont find the host using LE Read Buffer Size commands to get the buffer counts.

RE: Zephyr controller unable to discover characteristics after a while

Carles — Tue, 12 Sep 2017 07:56:40 GMT

The BlueZ maintainer mentions you have a "node" app that might be interfering with the correct functioning of the stack, so there's issues on the Host side here apparently.

RE: Zephyr controller unable to discover characteristics after a while

Carles — Tue, 12 Sep 2017 07:52:31 GMT

We are currently analyzing your log with BlueZ maintainers on IRC (freenode.net, #zephyr-bt). It seems you are injecting commands that can alter the flow of BlueZ. If you are interested in debugging this further please join us on IRC and we can probably help you out.

RE: Zephyr controller unable to discover characteristics after a while

vich — Mon, 11 Sep 2017 14:44:05 GMT

I see that you at some point have 14 connections, can you increase the CONFIG_BT_CTLR_TX_BUFFERS=7 to higher value, for example 20. I suspect, suspect, if host is sending more ACL data than 7 at any point. How much do you get as LE read buffer size on mynewt?

RE: Zephyr controller unable to discover characteristics after a while

bds — Mon, 11 Sep 2017 14:39:23 GMT

Yes, I also see this with mynewt. I think this is because I had a lot of devices (20 or so) advertising at 20 ms intervals, probably causing a lot of collisions on the advertising channels (which are also used for connection setup as I understood).

RE: Zephyr controller unable to discover characteristics after a while

vich — Mon, 11 Sep 2017 14:25:50 GMT

Hi bds,

I see in the snoop log, for example, first "connection failed to establish" at packet number 776, the host is trying to send ATT MTU request on a disconnected connection. This should be ok for the controller, as it will drop the data packet and not track it for num of complete packets. You will not get MTU responses for these disconnected connections. 776 56.021303 c3:71:31:b3:e8:fe () f7:11:72:f7:69:b5 (TP) ATT 11 Sent Exchange MTU Request, Client Rx MTU: 256

Do you see these "failed to establish connections" with mynewt?

RE: Zephyr controller unable to discover characteristics after a while

Carles — Mon, 11 Sep 2017 14:01:34 GMT

Can you try increasing the global TX and RX pools to at least twice the maximum number of connections?

CONFIG_BT_CTLR_RX_BUFFERS=32 CONFIG_BT_CTLR_TX_BUFFERS=32

and probably the HCI layer buffer count as well:

CONFIG_BT_RX_BUF_COUNT=32

RE: Zephyr controller unable to discover characteristics after a while

bds — Mon, 11 Sep 2017 13:56:17 GMT

I attached the file to my initial post.

RE: Zephyr controller unable to discover characteristics after a while

Carles — Mon, 11 Sep 2017 13:14:31 GMT

One additional request: could you give us your .config file in outdir/nrf52_pca10040/ ?

RE: Zephyr controller unable to discover characteristics after a while

Carles — Mon, 11 Sep 2017 13:13:26 GMT

OK Thanks for the info. We will need to try and reproduce the issue to find out what is going on.

RE: Zephyr controller unable to discover characteristics after a while

bds — Mon, 11 Sep 2017 13:10:24 GMT

Our peripherals are a design based on the nrf52, running a firmware based on your ble uart example. I'm pretty sure it's not the peripherals though. Because, without touching the peripherals, everything works again as soon as I reset the controller. Also, with Nimble, I don't have the same problem.

RE: Zephyr controller unable to discover characteristics after a while

Carles — Mon, 11 Sep 2017 13:04:04 GMT

Yep sorry, I did not realize. That said I would still recommend disabling the MSD. Can you let us know what firmware your peripherals are using in order to eliminate possibilities?

RE: Zephyr controller unable to discover characteristics after a while

bds — Mon, 11 Sep 2017 12:55:23 GMT

I was using the master. I doubt it's the Segger USB to UART, as connection setup and advertisements still worked fine (also see HCI log). Using myNewt Nimble seems to work better at the moment...

RE: Zephyr controller unable to discover characteristics after a while

Carles — Mon, 11 Sep 2017 12:31:06 GMT

Hi there,

I recall seeing something similar earlier this summer, but it was solved.

Can you specify which version of Zephyr you are running? Is it 1.8, 1.9 or master? Also this could be the Segger USB to UART bridge, make sure your MSD is disabled as per these instructions:

www.zephyrproject.org/.../nordic_segger.html

Thanks,

Carles