i2c issues in 6.18 on R4, but not r4pro (both mt7988 with i2c-mux on i2c2)

AngeloGioacchino Del Regno angelogioacchino.delregno at collabora.com
Wed Nov 5 04:30:28 PST 2025


Il 05/11/25 13:08, Frank Wunderlich ha scritto:
> Am 5. November 2025 12:51:23 MEZ schrieb Wolfram Sang <wsa+renesas at sang-engineering.com>:
>>
>>>> Maybe this option should be enabled by default or when the i2c-mux is
>>>> selected?
>>>
>>> That's what we were discussing. At least a warning will now get printed
>>> to the logs when booting suggesting the above solution.
>>
>> FYI, all the commits leading to this breakage are reverted now. Sorry
>> for your troubles!
> 
> Why? My issue was solved by adding GPIO_RESET... So it was fault on my side,sorry for bothering.
> 
> @angelo
> yes it is a final board BPI-R4 v1.1.
> 
> Why sometimes it works i guess it is because uboot may previously initialize the device (and without reset working it may be stuck in wrong state).

Heh, this is something that happens frequently.

> I'm not sure if my current flashed version had the i2c and i2cmux support,but i got it working on that board because of the connected eeprom (read mac address via tlv_eeprom as macs do not have fixed macs via efuse afaik).
> 
> Thanks for help so far.
> 

No worries, my pleasure (but I didn't do all that much anyway :P :P :P)

Cheers,
Angelo

> regards Frank





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