On 1/17/19 11:08, Viresh Kumar wrote: > 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 :) ah, of course, sorry was over-thinking this thing :) > > 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. > since this clock is enabled by the firmware, it seems to me that using CLK_IGNORE_UNUSED remains the best option.
