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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7ffdd81b-927e-46f1-976c-91fe2fee4f07@nvidia.com>
Date: Wed, 10 Dec 2025 04:08:42 +0000
From: Jon Hunter <jonathanh@...dia.com>
To: Krzysztof Kozlowski <krzk@...nel.org>, Aaron Kling <webgeek1234@...il.com>
Cc: Rob Herring <robh@...nel.org>, Conor Dooley <conor+dt@...nel.org>,
 Thierry Reding <thierry.reding@...il.com>, linux-kernel@...r.kernel.org,
 devicetree@...r.kernel.org, linux-tegra@...r.kernel.org
Subject: Re: [PATCH v4 3/5] memory: tegra186-emc: Support non-bpmp icc scaling


On 09/12/2025 05:53, Krzysztof Kozlowski wrote:
> On 09/12/2025 05:26, Aaron Kling wrote:
>> On Sat, Nov 22, 2025 at 6:01 AM Krzysztof Kozlowski <krzk@...nel.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@...dia.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.
> 
> Hm, I did not see the root cause identified, so maybe I missed something.
> 
> Anyway, I am waiting for the patchset to be retested and resent. And
> testing MUST include kernel development process rules, including how
> patches are taken - see maintainer soc profile. Any dependencies must be
> clearly marked.

Yes me too. I am happy to re-test any updates.

Jon

-- 
nvpublic