Hi Marc,

On Mon, Jun 21, 2021 at 9:37 AM Marc Kleine-Budde [off-list ref] wrote:

Can you test if
https://lore.kernel.org/r/20210621123436.2897023-1-mkl@pengutronix.de (local)
fixes your problem? We still have to check if lockdep complains...

I tested your series and I don't see the initial RCU errors after
launching the application, but
now it causes a storm of cansequence errors:

root@verdin-imx8mm:~# ./cantest.sh start
root@verdin-imx8mm:~# interface = can1, family = 29, type = 3, proto = 1
interface = can1, family = 29, type = 3, proto = 1
interface = can0, family = 29, type = 3, proto = 1
interface = can0, family = 29, type = 3, proto = 1
2020-02-12 19:36:05:161 sequence CNT:   1304, RX:     39    expected:
24    missing:   15    skt overfl d:    0 a:    0    delta:  15
incident: 1    seq_wrap RX: 5     sequ_wrap_expected: 5   overall
lost: 15
2020-02-12 19:36:05:406 sequence CNT:   3015, RX:    230    expected:
199    missing:   31    skt overfl d:    0 a:    0    delta:  31
incident: 1    seq_wrap RX: 11     sequ_wrap_expected: 11   overall
lost: 31
2020-02-12 19:36:05:455 sequence CNT:    742, RX:    238    expected:
230    missing:    8    skt overfl d:    0 a:    0    delta:   8
incident: 2    seq_wrap RX: 7     sequ_wrap_expected: 7   overall
lost: 23
2020-02-12 19:36:05:730 sequence CNT:   1287, RX:      8    expected:
 7    missing:    1    skt overfl d:    0 a:    0    delta:   1
incident: 3    seq_wrap RX: 12     sequ_wrap_expected: 12   overall
lost: 24
2020-02-12 19:36:05:746 sequence CNT:    991, RX:    228    expected:
223    missing:    5    skt overfl d:    0 a:    0    delta:   5
incident: 4    seq_wrap RX: 15     sequ_wrap_expected: 15   overall
lost: 29
....

For mcp2518fd usage with imx8mm: would you recommend SPI in PIO or DMA mode?
Looking at your imx6dl devicetree it seems you use DMA.

Thanks