Re: [PATCH v4 0/6] RK3588 and Rock 5B dts additions: thermal, OPP and fan

[Dragan Simic]

Hello Alexey and Heiko,

On 2024-05-28 11:49, Alexey Charkov wrote:
> On Mon, May 6, 2024 at 1:37 PM Alexey Charkov <alchark@xxxxxxxxx> 
> wrote:
> > This enables thermal monitoring and CPU DVFS on RK3588(s), as well as
> > active cooling on Radxa Rock 5B via the provided PWM fan.
> >
> > Some RK3588 boards use separate regulators to supply CPUs and their
> > respective memory interfaces, so this is handled by coupling those
> > regulators in affected boards' device trees to ensure that their
> > voltage is adjusted in step.
> >
> > This also enables the built-in thermal sensor (TSADC) for all boards
> > that don't currently have it enabled, using the default CRU based
> > emergency thermal reset. This default configuration only uses on-SoC
> > devices and doesn't rely on any external wiring, thus it should work
> > for all devices (tested only on Rock 5B though).
> >
> > The boards that have TSADC_SHUT signal wired to the PMIC reset line
> > can choose to override the default reset logic in favour of GPIO
> > driven (PMIC assisted) reset, but in my testing it didn't work on
> > Radxa Rock 5B - maybe I'm reading the schematic wrong and it doesn't
> > support PMIC assisted reset after all.
> >
> > Fan control on Rock 5B has been split into two intervals: let it spin
> > at the minimum cooling state between 55C and 65C, and then accelerate
> > if the system crosses the 65C mark - thanks to Dragan for suggesting.
> > This lets some cooling setups with beefier heatsinks and/or larger
> > fan fins to stay in the quietest non-zero fan state while still
> > gaining potential benefits from the airflow it generates, and
> > possibly avoiding noisy speeds altogether for some workloads.
> >
> > OPPs help actually scale CPU frequencies up and down for both cooling
> > and performance - tested on Rock 5B under varied loads. I've dropped
> > those OPPs that cause frequency reductions without accompanying 
> > decrease
> > in CPU voltage, as they don't seem to be adding much benefit in day to
> > day use, while the kernel log gets a number of "OPP is inefficient" 
> > lines.
> >
> > Note that this submission doesn't touch the SRAM read margin updates 
> > or
> > the OPP calibration based on silicon quality which the downstream 
> > driver
> > does and which were mentioned in [1]. It works as it is (also 
> > confirmed by
> > Sebastian in his follow-up message [2]), and it is stable in my 
> > testing on
> > Rock 5B, so it sounds better to merge a simple version first and then
> > extend when/if required.
> >
> > [1] 
> > https://lore.kernel.org/linux-rockchip/CABjd4YzTL=5S7cS8ACNAYVa730WA3iGd5L_wP1Vn9=f83RCORA@xxxxxxxxxxxxxx/
> > [2] 
> > https://lore.kernel.org/linux-rockchip/pkyne4g2cln27dcdu3jm7bqdqpmd2kwkbguiolmozntjuiajrb@gvq4nupzna4o/
> >
> > Signed-off-by: Alexey Charkov <alchark@xxxxxxxxx>
> > ---
>
> Hi Heiko,
>
> Do you think this can be merged for 6.11? Looks like there hasn't been
> any new feedback in a while, and it would be good to have frequency
> scaling in place for RK3588.
>
> Please let me know if you have any reservations or if we need any
> broader discussion.

As I promised earlier, I was going to test this patch series in detail.
Alas, I haven't managed to do that yet, :/ due to many reasons, but
I still remain firmly committed to doing that.

Is -rc4 the cutoff for 6.11?  If so, there's still time and I'll do my
best to test and review these patches as soon as possible.