On Wed, 09 Nov 2022 12:13:33 +0000, Hector Martin <marcan@xxxxxxxxx> wrote: > > On 24/10/2022 17.27, Marc Zyngier wrote: > > On Mon, 24 Oct 2022 05:39:24 +0100, > > Hector Martin <marcan@xxxxxxxxx> wrote: > >> > >> This driver implements CPU frequency scaling for Apple Silicon SoCs, > >> including M1 (t8103), M1 Max/Pro/Ultra (t600x), and M2 (t8112). > >> > >> Each CPU cluster has its own register set, and frequency management is > >> fully automated by the hardware; the driver only has to write one > >> register. There is boost frequency support, but the hardware will only > >> allow their use if only a subset of cores in a cluster are in > >> non-deep-idle. Since we don't support deep idle yet, these frequencies > >> are not achievable, but the driver supports them. They will remain > >> disabled in the device tree until deep idle is implemented, to avoid > >> confusing users. > >> > >> This driver does not yet implement the memory controller performance > >> state tuning that usually accompanies higher CPU p-states. This will be > >> done in a future patch. > >> > >> Signed-off-by: Hector Martin <marcan@xxxxxxxxx> > >> --- > >> drivers/cpufreq/Kconfig.arm | 9 + > >> drivers/cpufreq/Makefile | 1 + > >> drivers/cpufreq/apple-soc-cpufreq.c | 352 +++++++++++++++++++++++++++ > >> drivers/cpufreq/cpufreq-dt-platdev.c | 2 + > >> 4 files changed, 364 insertions(+) > >> create mode 100644 drivers/cpufreq/apple-soc-cpufreq.c > >> > > > > [...] > > > >> +static struct freq_attr *apple_soc_cpufreq_hw_attr[] = { > >> + &cpufreq_freq_attr_scaling_available_freqs, > >> + NULL, > >> + NULL, > > > > nit: extra NULL? > > That slot gets filled in later if boost is enabled, hence the need for > an extra terminating NULL in that case. Right. Consider placing a comment next to the first NULL so that someone else doesn't consider it useless and accidentally removes it... M. -- Without deviation from the norm, progress is not possible.