Re: [PATCH v4 3/5] memory: tegra186-emc: Support non-bpmp icc scaling

[Jon Hunter <jonathanh@nvidia.com>]

On 11/11/2025 12:05, Jon Hunter wrote:

...

>>> Thanks for testing. Something is not right because our boards are
>>> failing. So may be we are doing/testing something different. However,
>>> this should not break. So there is a problem here.
>>
>>
>> Did you meant: "So there is NO problem here"?
> 
> Nope. I mean that this is a problem here.
> 
>> I kept these for 10 days in linux-next and yesterday sent them in pull
>> request. If some patches are needed on top, they can still fit coming
>> merge window if sent soon.
> 
> Looking back I see it started failing with next-20251103. next-20251031 
> was fine. Reverting this commit on top of next-20251110 fixes the issue.
> 
> There may be a difference in the firmware being used. Our testing is 
> based upon an older NVIDIA L4T r32.5.1 release but nonetheless, we 
> should not break that.


OK, so I see what is happening here. The boot test that we are running 
has a 2 minute timeout and the board is now failing to boot within that 
time.

Adding some debug prints, I can see that initially the EMC clock 
frequency is 1600MHz and now after this change, on boot the EMC clock 
get set to 250MHz. Hence, the booting is now taking significantly longer 
and the test times out.

We definitely don't want to increase the timeout of the test. Any thoughts?

Jon

-- 
nvpublic