Failed to detect i2c device after kernel upgrade

robogil

Hi, I have updated my upboard to use kernel 5.4.0-1-generic for Ubuntu 18.04 server and since then I do not see my i2c device (mlx90641).
When listing the i2c devices using i2cdetect -li see

i2c-3 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-10 i2c i915 gmbus dpb I2C adapter
i2c-1 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-8 i2c i915 gmbus panel I2C adapter
i2c-6 i2c i915 gmbus ssc I2C adapter
i2c-4 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-11 i2c i915 gmbus dpd I2C adapter
i2c-2 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-0 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-9 i2c i915 gmbus dpc I2C adapter
i2c-7 i2c i915 gmbus vga I2C adapter
i2c-5 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-12 i2c DPDDC-D I2C adapter

i2cdetect -r -y 0

0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- UU -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

I have an additional upboard with the previous kernel (4.4.0-2-upboard) here is looks sorted:

i2c-0 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-1 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-2 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-3 i2c i915 gmbus ssc I2C adapter
i2c-4 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-5 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-6 i2c Synopsys DesignWare I2C adapter I2C adapter
i2c-7 i2c i915 gmbus vga I2C adapter
i2c-8 i2c i915 gmbus panel I2C adapter
i2c-9 i2c i915 gmbus dpc I2C adapter
i2c-10 i2c i915 gmbus dpb I2C adapter
i2c-11 i2c i915 gmbus dpd I2C adapter
i2c-12 i2c DPDDC-D I2C adapter

And I can see the device here where is should be (0X33):

i2cdetect -r -y 0

0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- 33 -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

What am I missing?

dorforerindoor

Hi, I'm having the same problem.
Has anyone managed to solve this?

eokerson

Try scanning other bus numbers. It's possible the bus numbering changed in the new kernel.
i2cdetect -r -y 1
i2cdetect -r -y 2
etc.