mx6ull: init_bandgap regression

[Ye Li]

Hi,

On 10/26/2025 7:55 PM, Fabio Estevam wrote:
> Hi Sven,
> 
> On Fri, Oct 24, 2025 at 6:23 AM Sven <u-boot at schwermer.no> wrote:
>>
>> Hi,
>>
>> We make an i.MX6ULL-based board that is built around the Phytec PCL063
>> SoM. We have noticed a regression between v2022.01 (good) and v2022.04
>> (bad). We have also found the following tags to be bad: v2022.07,
>> v2023.01, v2024.01. We have bisected this and found the culprit to be
>> c1af358c ("imx: mx6ull: fix REFTOP_VBGADJ setting"). This code still
>> appears to be unchanged on upstream master.
>>
>> These are the symptoms: Very few of the thousands of devices that we
>> manufacture (< 1%) fail to decompress a large XZ archive once in Linux
>> userspace. We have not found any form of memory testing or other load
>> that reproduces this issue. Reverting the offending patch fixes this
>> behavior on the affected devices.
> 
> Please send a patch with the revert.
> 
>> Perhaps the NXP folks could chime in on the intended behavior. And the
>> mismatch between commit message and comments mentioned in the offending
>> patch.
> 
> Peng, can you look at it, please?
> 
> Thanks


I once sent a fix to revert that patch, but it was rejected.
https://patchwork.ozlabs.org/project/uboot/patch/1646721735-125430-1-git-send-email-ye.li@nxp.com/

Best regards,
Ye Li