On Tue, 31 Jan 2023 at 17:57, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > On 30/01/2023 07:54, Hermes Zhang wrote: > > On 2023/1/29 18:58, Krzysztof Kozlowski wrote: > >> On 29/01/2023 03:36, Hermes Zhang wrote: > >>> This commit add a new property: cap-aggressive-pm to enable the > >> Do not use "This commit/patch". > >> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > > > > Done > > > >>> MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. > >> Why this is a property suitable for DT? IOW, why this isn't enabled always? > > > > This property will benfit for the power consumption, but it also may > > degradation in performance as it will prevent the > > > > the card from executing internal house-keeping operations in idle mode. > > So it's better to config it from DT. > > Why? DT is not for policy. How you described it, this is policy or > system tuning choice thus the job for Linux (OS), not for DT. So I will > repeat - why this property fits the purpose of DT (describe the hardware). > I guess the HW perspective here, is that it might not fit all platforms nor the actual eMMC/SD card to support this feature. However, it still seems like a policy rather than a strict HW constraint. Perhaps there is a way to figure out in the host driver, to conditionally set the MMC_CAP_AGGRESSIVE_PM for the host, when needed instead? Kind regards Uffe
