Hi Daniel, Thanks for your review feedback. On Fri, 6 Dec 2024 at 19:50, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: > > On 12/6/24 14:28, Krzysztof Kozlowski wrote: > > On Fri, Dec 06, 2024 at 12:39:56AM +0100, Daniel Lezcano wrote: > >>> +# SPDX-License-Identifier: GPL-2.0-only > >>> + > >>> +config EXYNOS_ACPM_PROTOCOL > >>> + tristate "Exynos Alive Clock and Power Manager (ACPM) Message Protocol" > >> > >> Given the importance of this driver where a lot of PM services rely on, does > >> it really make sense to allow it as a module ? Yes, we want the option to build it as a module so we can use the upstreamed driver with Generic Kernel Image (GKI) [1]. > >> > >> Some PM services may be needed very early in the boot process > >> > > > > If it works as module e.g. on Android, it is beneficial. I think the > > platform was booting fine without it, at least to some shell, so I can > > imagine this can be loaded a bit later. > > Usually the firmware sets the frequency to the maximum in order to boot > the kernel as fast as possible. That may lead to thermal issues at boot > time where the thermal framework won't be able to kick in as some > components will depends on ACPM while the system stays at its highest > performance state. That isn't an issue here as the Pixel 6 bootloader leaves CPUs at mid point frequencies during boot. I would actually expect most modern phone bootloaders (since the launch of GKI at least) to do something similar as it is a requirement for Generic Kernel Image (GKI) [1] that all the SoC drivers are built as modules. [1] https://source.android.com/docs/core/architecture/kernel/generic-kernel-image Thanks, Peter
