Re: [BUG] SPD5118 Intermittent MR11 Corruption During Suspend/Resume

[Guenter Roeck]

Hi Matthew,

On 9/1/26 09:31, Matthew Bettencourt wrote:
> Hello Guenter,
>
> I added additional logging into the piix4_transaction(). I will put the function call on the bottom. But as you guessed we are seeing not just MR11 corruption but also can trigger on other addresses as well. I was running the suspend/resume cycle and caught on both MR11 issue and else where. Here is the dmesg log output.
>
> --- Other PIIX4 transation ---
...
> [29287.881787] [ T204580] i2c i2c-12: [PIIX4 REGISTER MUTATION DETECTED] Pre: (CMD=0x1a, ADD=0xa3) -> Post: (CMD=0x01, ADD=0x45) | DAT0=0xff
...
> [29312.945873] [ T204570] i2c i2c-12: [PIIX4 REGISTER MUTATION DETECTED] Pre: (CMD=0x0b, ADD=0xa7) -> Post: (CMD=0x01, ADD=0x45) | DAT0=0xff

It may be a coincidence, but the two failed accesses are exactly 25 seconds apart.

Would it be possible to drop the messages except for the failures and run long-term
accesses (for example by reading the temperatures and/or the nvmem continuously) ?
You should find the nvmem at /sys/bus/nvmem/devices/0-005[13]/nvmem.

It might be useful to know if this only happens during suspend/resume cycles
or if it happens all the time, if it happens randomly or in specific intervals,
and if the failure pattern is always the same.

Thanks,
Guenter