On 7/8/2019 10:55 AM, anson.hu...@nxp.com wrote:
> To reduce the suspend/resume latency, CPU's max supported frequency
> should be used during low level suspend/resume phase, "opp-suspend"
> property is NOT feasible since OPP defined in DT could be NOT supported
> according to speed garding and market segment fuse settings. So we
> can assign the cpufreq policy's suspend_freq with max available
> frequency provided by cpufreq driver.
>
> Signed-off-by: Anson Huang <anson.hu...@nxp.com>
> diff --git a/drivers/cpufreq/imx-cpufreq-dt.c
> b/drivers/cpufreq/imx-cpufreq-dt.c
> +static int __init imx_cpufreq_dt_setup_suspend_opp(void)
> +{
> + struct cpufreq_policy *policy = cpufreq_cpu_get(0);
> +
> + policy->suspend_freq = cpufreq_quick_get_max(0);
> +
> + return 0;
> +}
> +late_initcall(imx_cpufreq_dt_setup_suspend_opp);
The imx-cpufreq-dt driver is built as a module by default and this patch
produces an error:
In file included from ../drivers/cpufreq/imx-cpufreq-dt.c:11:
../include/linux/module.h:131:42: error: redefinition of ‘__inittest’
static inline initcall_t __maybe_unused __inittest(void) \
^~~~~~~~~~
../include/linux/device.h:1656:1: note: in expansion of macro ‘module_init’
module_init(__driver##_init); \
^~~~~~~~~~~
As far as I can tell late_initcall is not supported for modules.
Viresh: "max freq as suspend freq" is something that could be useful for
other SOC families. The hardware can suspend at any freq; it's just that
the highest one makes sense because it makes suspend/resume slightly faster.
Could this behavior be pushed to cpufreq-dt as a bool flag inside struct
cpufreq_dt_platform_data?
Only a few other platforms use this, most others pass NULL like imx. But
passing custom SOC-specific flags to cpufreq-dt makes a lot of sense
--
Regards,
Leonard
