Re: [PATCH v4 0/4] Enable ICE clock scaling

[Abhinaba Rakshit <abhinaba.rakshit@oss.qualcomm.com>]

On Thu, Jan 29, 2026 at 01:17:51PM +0100, Konrad Dybcio wrote:
> On 1/28/26 9:46 AM, Abhinaba Rakshit wrote:
> > Introduce support for dynamic clock scaling of the ICE (Inline Crypto Engine)
> > using the OPP framework. During ICE device probe, the driver now attempts to
> > parse an optional OPP table from the ICE-specific device tree node to
> > determine minimum and maximum supported frequencies for DVFS-aware operations.
> > API qcom_ice_scale_clk is exposed by ICE driver and is invoked by UFS host
> > controller driver in response to clock scaling requests, ensuring coordination
> > between ICE and host controller.
> > 
> > For MMC controllers that do not support clock scaling, the ICE clock frequency
> > is kept aligned with the MMC controller’s clock rate (TURBO) to ensure
> > consistent operation.
> 
> You skipped that bit, so I had to do a little digging..
> 
> This paragraph sounds scary on the surface, as leaving a TURBO vote hanging
> would absolutely wreck the power/thermal profile of a running device,
> however sdhci-msm's autosuspend functions quiesce the ICE by calling
> qcom_ice_suspend()
> 
> I think you're missing a dev_pm_opp_set(dev, NULL) or so in that function
> and a mirrored restore in _resume

Thanks for pointing this out, its an important piece which is missed.
We can use dev_pm_opp_set_rate(dev, 0/min_freq) in _suspend and restore the
suspended frequency in the _resume. Something similar which is used by sdhci-msm.