On 2024-11-10 22:16, Heiko Stübner wrote:
Am Sonntag, 10. November 2024, 21:47:15 CET schrieb Dragan Simic:
On 2024-11-10 21:08, Heiko Stübner wrote:
Am Sonntag, 10. November 2024, 19:44:31 CET schrieb Dragan Simic:
The regulator-{min,max}-microvolt values for the vdd_gpu regulator in the PinePhone Pro device dts file are too restrictive, which prevents the highest GPU OPP from being used, slowing the GPU down unnecessarily. Let's fix that by making the regulator-{min,max}-microvolt values less strict, using the voltage range that the Silergy SYR838 chip used for the vdd_gpu regulator is actually capable of producing. [1][2]
This also eliminates the following error messages from the kernel log:
core: _opp_supported_by_regulators: OPP minuV: 1100000 maxuV: 1150000, not supported by regulator panfrost ff9a0000.gpu: _opp_add: OPP not supported by regulators (800000000)
These changes to the regulator-{min,max}-microvolt values make the PinePhone Pro device dts consistent with the dts files for other Rockchip RK3399-based boards and devices. It's possible to be more strict here, by specifying the regulator-{min,max}-microvolt values that don't go outside of what the GPU actually may use, as the consumer of the vdd_gpu regulator, but those changes are left for a later directory-wide regulator cleanup.
With the Pinephone Pro using some sort of special-rk3399, how much of "the soc variant cannot use the highest gpu opp" is in there, and just the original implementation is wrong?
Good question, I already asked it myself. I'm unaware of any kind of GPU-OPP-related restrictions when it comes to the PinePhone-Pro-specific RK3399S. Furthermore, "the word on the street" is that the RK3399S can work perfectly fine even at the couple of "full-fat" RK3399 CPU OPPs that are not defined for the RK3399S, and the only result would be the expected higher power consumption and a bit more heat generated.
In the past we already had people submit higher cpu OPPs with the reasoning "the cpu runs fine with it", but which where outside of the officially specified frequencies and were essentially overclocking the CPU cores and thus possibly reducing its lifetime.
Sure, having higher-frequency OPPs working doesn't mean that's the way the SoC is intended to be used. It also doesn't mean that all samples of the same SoC would work reliably with higher-frequency OPPs.
So "it runs fine" is a bit of thin argument ;-) . I guess for the gpu it might not matter too much, compared to the cpu cores, but I still like the safe sides - especially for the mainline sources.
Just to clarify, in this particular case the above-mentioned "word on the street" came straight from TL Lim, the founder of Pine64, back when we recently discussed what actually makes the RK3399S a special variant of the RK3399. He basically forwarded what Rockchip said him about the RK3399S as a special variant.
One of the troubles, in this particular case, is there's no official datasheet that describes the RK3399S, so it's all a bit up to "the word on the street", I'm afraid.
I guess we'll wait for people to test the change and go from there ;-) .
Sure, but even with a few "tested, works for me" reports, we still won't be able to stop relying on the above-described "word on the street", simply because e.g. even CPU core overclocks, which would of course be wrong, perhaps would work just fine for some people. I hope I'm conveying this in an understandable way. :)
This just reaffirms that no known GPU OPP restrictions exist. Even if they existed, enforcing them _primarily_ through the constraints of the associated voltage regulator would be the wrong approach. Instead, the restrictions should be defined primarily through the per-SoC-variant GPU OPPs, which are, to my best knowledge, not known to be existing for the RK3399S SoC variant.
Yes, that is what I was getting at, if that is a limiting implementation it is of course not done correctly, but I'd like to make sure.
Indeed, I'd also like to have it all checked as much as possible. I'll try to extract the device dts from the test Android image that was supposedly provided directly by Rockchip for the PinePhone Pro, and check what's actually defined inside it.
Of course Pine's development model doesn't help at all in that regard. There isn't even a "vendor" kernel source it seems. [0]
I see, it's a bit confusing, so I'll try to explain. See, Pine64, as an SBC and device manufacturer, basically has no official software development model or an associated team. Instead, the entire software development, be it low-level or high-level software, is left to the broader community made primarily of various individuals, who all have different approaches to their work.
That's why I referred to "the word on the street" originally. I hope it all makes more sense now. :)
[0] https://wiki.pine64.org/wiki/PinePhone_Pro_Development#Kernel states "There's no canonical location for Pinephone Pro Linux kernel development,"