Hi Dragan,
On 3/23/25 11:19 AM, Dragan Simic wrote:
Hello Quentin,
Thanks for your comments! Please see some responses below.
On 2025-03-21 10:53, Quentin Schulz wrote:
On 3/21/25 4:28 AM, Dragan Simic wrote:
The differences in the vendor-approved CPU and GPU OPPs for the standard Rockchip RK3588 variant [1] and the industrial Rockchip RK3588J variant [2] come from the latter, presumably, supporting an extended temperature range that's usually associated with industrial applications, despite the two SoC variant datasheets specifying the same upper limit for the allowed ambient temperature for both variants. However, the lower temperature limit is
RK3588 is rated for 0-80°C, RK3588J for -40-85°C, c.f. Recommended Operating Conditions, Table 3-2, Ambient Operating Temperature.
Indeed, which is why I specifically wrote "specifying the same upper limit", because having a lower negative temperature limit could hardly put the RK3588J in danger of overheating or running hotter. :)
""" despite the two SoC variant datasheets specifying the same upper limit for the allowed temperature for both variants """
is incorrect. The whole range is different, yes it's only a 5°C difference for the upper limit, but they still are different.
specified much lower for the RK3588J variant. [1][2]
To be on the safe side and to ensure maximum longevity of the RK3588J SoCs, only the CPU and GPU OPPs that are declared by the vendor to be always safe for this SoC variant may be provided. As explained by the vendor [3] and according to its datasheet, [2] the RK3588J variant can actually run safely at higher CPU and GPU OPPs as well, but only when not enjoying the assumed extended temperature range that the RK3588J, as an SoC variant targeted
"only when not enjoying the assumed extended temperature range" is extrapolated by me/us and not confirmed by Rockchip themselves. I've asked for a statement on what "industrial environment" they specify in the Normal Mode explanation means since it's the only time they use the term. I've yet to receive an answer. The only thing Rockchip in their datasheet is that the overdrive mode will shorten lifetime when used for a long time, especially in high temperature conditions. It's not clear whether we can use the overdrive mode even within the RK3588 typical range of operation.
True. I'll see to rephrase the patch description a bit in the v2, to avoid this kind of speculation. I mean, perhaps the speculation is right, but it hasn't been confirmed officially by Rockchip.
Speculation is fine, but it should be worded as such.
[...]
The provided RK3588J CPU OPPs follow the slightly debatable "provide only the highest-frequency OPP from the same-voltage group" approach that's been
Interesting that we went for a different strategy for the GPU OPPs :)
Good point, and I'm fully aware of that. :) Actually, I'm rather sure that omitting the additional CPU OPPs does no good to us, but I didn't want to argue about that when they were dropped originally, before I can have some hard numbers to prove it in a repeatable way.
I assume we'll have some patch in the future with those added and those hard numbers you're talking about, so looking forward to seeing it on the ML :)
[...]
Helped-by: Quentin Schulz quentin.schulz@cherry.de
Reported-by/Suggested-by?
I don't see Helped-by in https://eur02.safelinks.protection.outlook.com/? url=https%3A%2F%2Fwww.kernel.org%2Fdoc%2Fhtml%2Flatest%2Fprocess%2Fsubmitting-patches.html%23using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes&data=05%7C02%7Cquentin.schulz%40cherry.de%7Cdc754791b6844506b11c08dd69f444a7%7C5e0e1b5221b54e7b83bb514ec460677e%7C0%7C0%7C638783220330058516%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=4bv9pUh6aSD0GVLJ4Zvuyvox1K0xxwf83KXX86QsvMo%3D&reserved=0
I see 2496b2aaacf137250f4ca449f465e2cadaabb0e8 got the Helped-by replaced by a Suggested-by for example, but I see other patches with Helped-by... if that is a standard trailer for kernel patches, then maybe we should add it to that doc?
Actually, I already tried to get the Helped-by tag added to the kernel documentation, by submitting a small patch series. [*] Unfortunately, it got rejected. :/
However, Heiko accepts Helped-by tags and nobody higher up the tree seems to complain, so we should be fine. :) It isn't the case with all maintainers, though.
[*] https://eur02.safelinks.protection.outlook.com/? url=https%3A%2F%2Flore.kernel.org%2Fall%2Fcover.1730874296.git.dsimic%40manjaro.org%2FT%2F%23u&data=05%7C02%7Cquentin.schulz%40cherry.de%7Cdc754791b6844506b11c08dd69f444a7%7C5e0e1b5221b54e7b83bb514ec460677e%7C0%7C0%7C638783220330070422%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=3dZgSG%2FBT6f%2Ffqs7D30HvEl18SzqYPwNeUGWBZfMAqM%3D&reserved=0
Are you trying to up the numbers of Helped-by in commit logs to make it a reasonable request to add the trailer in the documentation :) ?
Cheers, Quentin