I2cdetect error output : tegra-i2c : no acknowledge from address

jhjo · August 25, 2022, 11:06am

Hello,

We use Xavier AGX on our custom carrier board.
I tested with i2cdetect as shown below :

sudo i2cdetect -y -r 8

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: – – – – – – – – – – – – –

10: – – – – – – – – – – – – – – – –

20: – – – – – – – – – – – – – – – –

30: – – – – – – – – – – – – – – – –

40: – – – – – – – – – – – – – – – –

50: – – – – – – – – – – – – – – – –

60: – – – – – – – – – – – – – – – –

70: – – – – – – – –

But it also printed error messages:

#00: [ 927.634443] tegra-i2c 31e0000.i2c: no acknowledge from address 0x3

– [ 927.634842] tegra-i2c 31e0000.i2c: no acknowledge from address 0x4

– [ 927.635207] tegra-i2c 31e0000.i2c: no acknowledge from address 0x5

– [ 927.635543] tegra-i2c 31e0000.i2c: no acknowledge from address 0x6

– [ 927.635876] tegra-i2c 31e0000.i2c: no acknowledge from address 0x7

– [ 927.636207] tegra-i2c 31e0000.i2c: no acknowledge from address 0x8

– [ 927.636545] tegra-i2c 31e0000.i2c: no acknowledge from address 0x9

– [ 927.636869] tegra-i2c 31e0000.i2c: no acknowledge from address 0xa

– [ 927.637199] tegra-i2c 31e0000.i2c: no acknowledge from address 0xb

– [ 927.637948] tegra-i2c 31e0000.i2c: no acknowledge from address 0xc

– [ 927.638341] tegra-i2c 31e0000.i2c: no acknowledge from address 0xd

– [ 927.638696] tegra-i2c 31e0000.i2c: no acknowledge from address 0xe

– [ 927.639070] tegra-i2c 31e0000.i2c: no acknowledge from address 0xf

–

10: [ 927.639439] tegra-i2c 31e0000.i2c: no acknowledge from address 0x10

– [ 927.640402] tegra-i2c 31e0000.i2c: no acknowledge from address 0x11

– [ 927.647013] tegra-i2c 31e0000.i2c: no acknowledge from address 0x12

– [ 927.653361] tegra-i2c 31e0000.i2c: no acknowledge from address 0x13

…

Does this mean there is no device connected to i2c gpio ports?
And what are those error messages are trying to saying?

JerryChang · August 26, 2022, 3:28am

hello jhjo,

i2cdetect utility it scan an I2C bus for devices. you may also output a list of installed busses before checking, $ sudo i2cdetect -l
do you have physical device connected to i2c-8, 31e0000.i2c? do yo have regulator settings config correctly?

jhjo · August 26, 2022, 10:46am

Hello JerryChang,

aaa@aaa-desktop:~$ i2cdetect -l
i2c-3 i2c 3190000.i2c I2C adapter
i2c-1 i2c c240000.i2c I2C adapter
i2c-8 i2c 31e0000.i2c I2C adapter
i2c-6 i2c 31c0000.i2c I2C adapter
i2c-4 i2c Tegra BPMP I2C adapter I2C adapter
i2c-2 i2c 3180000.i2c I2C adapter
i2c-0 i2c 3160000.i2c I2C adapter
i2c-7 i2c c250000.i2c I2C adapter
i2c-5 i2c 31b0000.i2c I2C adapter
aaa@aaa-desktop:~$ i2cdetect -y -r 4
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – – – – – – – – – – – – –
10: – – – – – – – – – – – – – – – –
20: 20 – – – – – – – – – – – – – – –
30: – – – – – – – – – – – – UU – – –
40: 40 – – – – – – – – – – – UU – – –
50: – – – – – – – – – – – – – – – –
60: – – – – – – – – UU – – – – – – –
70: – – – – – – – –
aaa@aaa-desktop:~$ i2cget -y 4 0x20
0xff
aaa@aaa-desktop:~$ i2cget -y 4 0x40
0xff
aaa@aaa-desktop:~$ i2cset -y 4 0x20 0x88
[16214.693473] i2c i2c-4: tegra_bpmp_i2c_req ret -13
[16214.693636] i2c i2c-4: — message dump for debugging —
[16214.693762] i2c i2c-4: addr 0x20 flags 0x0 len 1 data:
[16214.693859] i2c i2c-4: 88
[16214.693917] i2c i2c-4:
Error: Write failed
aaa@aaa-desktop:~$ i2cset -y 4 0x40 0x88
[16221.107552] i2c i2c-4: tegra_bpmp_i2c_req ret -13
[16221.107798] i2c i2c-4: — message dump for debugging —
[16221.108019] i2c i2c-4: addr 0x40 flags 0x0 len 1 data:
[16221.108127] i2c i2c-4: 88
[16221.108201] i2c i2c-4:
Error: Write failed

I’ve found other buses. And tested some…

We use MAX9296 with for the i2c.
I’d like any suggestion if you have.
I’ve had not that enough experience in these area…

Thank you…

JerryChang · August 29, 2022, 2:00am