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SubjectRe: [PATCH 08/13] clk: qcom: hfpll: CLK_IGNORE_UNUSED
On 17-01-19, 09:38, Jorge Ramirez wrote:
> COMMON_CLK_DISABLED_UNUSED relies on the enable_count reference counter
> to disable the clocks that were enabled by the firwmare and not by the
> drivers.
>
> the cpufreq driver does not enable the cpu clock.
>
> so when clk_change_rate is called, the enable_count counter is not
> incremented and therefore it just remains null since this was enabled by
> the firmware.
>
> I tried doing:
>
> diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> index e58bfcb..5a9f83e 100644
> --- a/drivers/cpufreq/cpufreq-dt.c
> +++ b/drivers/cpufreq/cpufreq-dt.c
> @@ -124,6 +124,10 @@ static int resources_available(void)
> return ret;
> }
>
> + ret = clk_prepare_enable(cpu_clk);
> + if (ret)
> + return ret;
> +
> clk_put(cpu_clk);
>
> name = find_supply_name(cpu_dev);
>
>
> and that removed the need for CLK_IGNORE_UNUSED. But I am not sure of
> the system wide consequences of that change to cpufreq.

If the cpufreq driver enables it then it should disable it on exit as
well, right ? And in that case if you unload your driver's module, you
will hang the system as the clock will get disabled :)

Every other platform must either be marking it with CLK_IGNORE_UNUSED
or they must be doing clk_enable from somewhere, maybe the CPU online
path, not sure though.

--
viresh

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