RE: Bluetooth Mesh MPU fault with Logging V2

user116211 — Thu, 09 Jun 2022 08:25:38 GMT

It seems I made a mistake. Everything seemed to work, but when the device gets provisioned it still causes an MPU fault. I use the nRF mesh app (iOS version) to provision the device with the BT mesh light fixture example.

▒*** Booting Zephyr OS build v2.7.99-ncs1-1  ***
Initializing...
[Bluetooth initialized
Mesh initialized
Successfully enabled LC server
00:00:00.012,176] <inf> fs_nvs: 6 Sectors of 4096 bytes
[00:00:00.012,176] <inf> fs_nvs: alloc wra: 0, f90
[00:00:00.012,207] <inf> fs_nvs: data wra: 0, 44
[00:00:00.012,390] <inf> sdc_hci_driver: SoftDevice Controller build revision:
                                         0e e7 c5 66 67 18 3c ac  b3 d2 cc 81 a3 dc f1 c0 |...fg.<. ........
                                         c0 36 02 22                                      |.6."
[00:00:00.017,517] <inf> bt_hci_core: No ID address. App must call settings_load()
[00:03:07.352,600] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
[00:03:09.456,726] <err> os: ***** MPU FAULT *****
[00:03:09.456,756] <err> os:   Stacking error (context area might be not valid)
[00:03:09.456,756] <err> os:   Data Access Violation
[00:03:09.456,756] <err> os:   MMFAR Address: 0x20005518
[00:03:09.456,787] <err> os: r0/a1:  0xd8043b82  r1/a2:  0x5caeff8e  r2/a3:  0xef0cac29
[00:03:09.456,787] <err> os: r3/a4:  0xe4e1b764 r12/ip:  0xad304278 r14/lr:  0x9bb478d9
[00:03:09.456,787] <err> os:  xpsr:  0x21000000
[00:03:09.456,817] <err> os: Faulting instruction address (r15/pc): 0x0004d6fe
[00:03:09.456,848] <err> os: >>> ZEPHYR FATAL ERROR 2: Stack overflow on CPU 0
[00:03:09.456,878] <err> os: Current thread: 0x200029c0 (BT RX)
▒*** Booting Zephyr OS build v2.7.99-ncs1-1  ***system

RE: Bluetooth Mesh MPU fault with Logging V2

user116211 — Thu, 09 Jun 2022 08:07:35 GMT

Hi, small update. I found this Q&A on Nordic devzone which had a similar issue. I increased the main stack size `CONFIG_MAIN_STACK_SIZE` and flashed it to the DK. In the Bluetooth mesh light fixture example, this solved it for both log modes. For my own application, this method solved the issue for deferred logging mode. But for log mode immediate, I got a slightly different error. I increased the main stack size up to 8192.

*** Booting Zephyr OS build v2.7.99-ncs1-1  ***
[00:00:00.010,681] <inf> App: Initializing...
[00:00:00.022,430] <inf> fs_nvs: 6 Sectors of 4096 bytes
[00:00:00.028,503] <inf> fs_nvs: alloc wra: 2, c40
[00:00:00.034,027] <inf> fs_nvs: data wra: 2, 1d4
[00:00:00.104,309] <inf> sdc_hci_driver: SoftDevice Controller build revision:
                                         0e e7 c5 66 67 18 3c ac  b3 d2 cc 81 a3 dc f1 c0 |...fg.<. ........
                                         c0 36 02 22                                      |.6."
[00:00:00.137,664] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.160,888] <inf> bt_hci_core: HW Variant: nRF52x (0x0002)
[00:00:00.182,739] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 14.50663 Build 1008
[00:00:00.209,838] <inf> bt_hci_core: No ID address. App must call settings_load()
[00:00:00.233,184] <inf> App: Bluetooth initialized
[00:00:00.274,322] <inf> bt_hci_core: Identity: C9:C6:04:AF:B8:52 (random)
[00:00:00.296,997] <inf> bt_hci_core: HCI: version 5.2 (0x0b) revision 0x12fe, manufacturer 0x0059
[00:00:00.321,838] <inf> bt_hci_core: LMP: version 5.2 (0x0b) subver 0x12fe
[00:00:00.344,848] <inf> bt_mesh_prov_device: Device UUID: 00000000-0000-0080-f744-ea62d0b23649
[00:00:00.370,727] <inf> App: Mesh initialized
[00:00:00.391,113] <inf> App: Boot count: 786
[00:00:00.455,902] <err> os: ***** MPU FAULT *****
[00:00:00.476,623] <err> os:   Stacking error (context area might be not valid)
[00:00:00.499,938] <err> os:   Data Access Violation
[00:00:00.520,874] <err> os:   MMFAR Address: 0x20005ad8
[00:00:00.542,175] <err> os: r0/a1:  0x3a579300  r1/a2:  0xbc1a9c0b  r2/a3:  0xe8bc7378
[00:00:00.566,345] <err> os: r3/a4:  0x8565b192 r12/ip:  0x58d21214 r14/lr:  0x5fdb17e0
[00:00:00.590,515] <err> os:  xpsr:  0x21000000
[00:00:00.611,022] <err> os: Faulting instruction address (r15/pc): 0x0004086c
[00:00:00.634,307] <err> os: >>> ZEPHYR FATAL ERROR 2: Stack overflow on CPU 0
[00:00:00.657,623] <err> os: Current thread: 0x20002cf0 (BT Mesh adv)
[00:00:00.700,103] <err> fatal_error: Resetting system

For me, deferred logging v2 is enough. But I'm curious as to why it still doesn't work with log mode immediate v2 in my own application?