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

Krzysztof Kozlowski
2025-11-11T11:16:59Z

On 11/11/2025 12:13, Jon Hunter wrote:
>>>>> +
>>>>> if (tegra_bpmp_mrq_is_supported(emc->bpmp, MRQ_EMC_DVFS_LATENCY)) {
>>>>> err = tegra186_emc_get_emc_dvfs_latency(emc);
>>>>> if (err)
>>>>>
>>>>
>>>>
>>>> FYI, this patch is causing a boot regression on Tegra194 devices. I
>>>> noticed that tegra194-p2972-0000 and tegra194-p3509-0000+p3668-0000 are
>>>> no longer booting and bisect is pointing to this. I will have a closer
>>>> look and try to see why this is.
>>>
>>> Interesting. Both were booting for me during my verification, though
>>> my use case involves the dt changes that I don't believe have been
>>> picked up yet. Thought I had explicitly verified without the dt
>>> changes too, though. Since I was asked to do so on this or one of the
>>> other similar series. I will try to check linux-next as-is soon.
>>
>> I just built next-20251110 using the standard arm64 defconfig and
>> flashed the resulting Image and dtb's to p2972 and p3518 (p3509+p3668)
>> and both booted to cli on a barebones busybox ramdisk. I do not see
>> any errors from tegra-mc, and the only error I see from tegra186-emc
>> is that it can't find the opp tables, which is expected without the dt
>> changes, and is not fatal.
>
> 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"?

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.

Best regards,
Krzysztof