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

Aaron Kling
2025-12-09T04:26:28Z

On Sat, Nov 22, 2025 at 6:01 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On 21/11/2025 12:21, Jon Hunter wrote:
> >
> > On 12/11/2025 07:21, Aaron Kling wrote:
> >> On Wed, Nov 12, 2025 at 12:18 AM Jon Hunter <jonathanh@nvidia.com> wrote:
> >>>
> >>>
> >>> On 11/11/2025 23:17, Aaron Kling wrote:
> >>>
> >>> ...
> >>>
> >>>> Alright, I think I've got the picture of what's going on now. The
> >>>> standard arm64 defconfig enables the t194 pcie driver as a module. And
> >>>> my simple busybox ramdisk that I use for mainline regression testing
> >>>> isn't loading any modules. If I set the pcie driver to built-in, I
> >>>> replicate the issue. And I don't see the issue on my normal use case,
> >>>> because I have the dt changes as well.
> >>>>
> >>>> So it appears that the pcie driver submits icc bandwidth. And without
> >>>> cpufreq submitting bandwidth as well, the emc driver gets a very low
> >>>> number and thus sets a very low emc freq. The question becomes... what
> >>>> to do about it? If the related dt changes were submitted to
> >>>> linux-next, everything should fall into place. And I'm not sure where
> >>>> this falls on the severity scale since it doesn't full out break boot
> >>>> or prevent operation.
> >>>
> >>> Where are the related DT changes? If we can get these into -next and
> >>> lined up to be merged for v6.19, then that is fine. However, we should
> >>> not merge this for v6.19 without the DT changes.
> >>
> >> The dt changes are here [0].
> >
> > To confirm, applying the DT changes do not fix this for me. Thierry is
> > having a look at this to see if there is a way to fix this.
> >
> > BTW, I have also noticed that Thierry's memory frequency test [0] is
> > also failing on Tegra186. The test simply tries to set the frequency via
> > the sysfs and this is now failing. I am seeing ..

With this patch dropped from -next, what needs to happen to get it
requeued? I gave an analysis over two weeks ago and have seen no
response since.

Aaron