Messages in this thread | | | Subject | Re: [PATCH v1] arch_topology: Adjust initial CPU capacities with current freq | From | Dietmar Eggemann <> | Date | Fri, 10 Jan 2020 13:01:24 +0100 |
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On 10/01/2020 12:37, Sudeep Holla wrote: > On Thu, Jan 09, 2020 at 03:52:14PM +0800, Jeffy Chen wrote: >> The CPU freqs are not supposed to change before cpufreq policies >> properly registered, meaning that they should be used to calculate the >> initial CPU capacities. >> >> Doing this helps choosing the best CPU during early boot, especially >> for the initramfs decompressing. >> >> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> > > [...] > >> @@ -146,10 +153,15 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) >> return false; >> } >> } >> - capacity_scale = max(cpu_capacity, capacity_scale); >> raw_capacity[cpu] = cpu_capacity; >> pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n", >> cpu_node, raw_capacity[cpu]); >> + >> + cpu_clk = of_clk_get(cpu_node, 0); >> + if (!PTR_ERR_OR_ZERO(cpu_clk)) >> + per_cpu(max_freq, cpu) = clk_get_rate(cpu_clk) / 1000; >> + >> + clk_put(cpu_clk); > > I don't like to assume DVFS to be supplied only using 'clk'. So NACK! > We have other non-clk mechanism for CPU DVFS and this needs to simply > use cpufreq APIs to get frequency value if required.
To support this, it's failing on my Arm64 Juno board.
... [ 0.084858] CPU1 cpu_clk=-517 [ 0.087961] CPU2 cpu_clk=-517 [ 0.091005] CPU0 cpu_clk=-517 [ 0.094121] CPU3 cpu_clk=-517 [ 0.097248] CPU4 cpu_clk=-517 [ 0.100415] CPU5 cpu_clk=-517 ...
Since you're on a big.LITTLE platform, did you specify 'capacity-dmips-mhz' for CPUs to be able to distinguish big and little CPUs before CPUfreq kicks in?
$ grep capacity-dmips-mhz ./arch/arm64/boot/dts/arm/juno.dts capacity-dmips-mhz = <1024>; capacity-dmips-mhz = <1024>; capacity-dmips-mhz = <578>; capacity-dmips-mhz = <578>; capacity-dmips-mhz = <578>; capacity-dmips-mhz = <578>;
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