Messages in this thread | | | Date | Mon, 19 Dec 2022 17:01:58 -0600 | Subject | Re: [PATCH v8 05/13] cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param() | From | "Limonciello, Mario" <> |
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On 12/19/2022 00:40, Perry Yuan wrote: > There are some other amd pstate driver working mode to be supported.
Perhaps:
The amd-pstate driver may support multiple working modes. Introduce a variable to keep track of which mode is currently enabled.
> Here we use cppc_state var to indicate which mode is enabled. > This change will help to simplify the the amd_pstate_param() to choose > which mode used for the following driver registeration.
s/registeration/registration/
> > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > Signed-off-by: Wyes Karny <wyes.karny@amd.com> > --- > drivers/cpufreq/amd-pstate.c | 35 +++++++++++++++++++++++++++-------- > include/linux/amd-pstate.h | 29 +++++++++++++++++++++++++++++ > 2 files changed, 56 insertions(+), 8 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index c17bd845f5fc..861a905f9324 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -60,7 +60,18 @@ > * module parameter to be able to enable it manually for debugging. > */ > static struct cpufreq_driver amd_pstate_driver; > -static int cppc_load __initdata; > +static int cppc_state = AMD_PSTATE_DISABLE; > + > +static inline int get_mode_idx_from_str(const char *str, size_t size) > +{ > + int i; > + > + for (i=0; i < AMD_PSTATE_MAX; i++) { > + if (!strncmp(str, amd_pstate_mode_string[i], size)) > + return i; > + } > + return -EINVAL; > +} > > static inline int pstate_enable(bool enable) > { > @@ -628,7 +639,7 @@ static int __init amd_pstate_init(void) > * enable the amd_pstate passive mode driver explicitly > * with amd_pstate=passive in kernel command line > */ > - if (!cppc_load) { > + if (cppc_state == AMD_PSTATE_DISABLE) { > pr_debug("driver load is disabled, boot with amd_pstate=passive to enable this\n");
Presumably this message needs to be changed since there are different modes that can be used to enable it now.
> return -ENODEV; > } > @@ -671,16 +682,24 @@ device_initcall(amd_pstate_init); > > static int __init amd_pstate_param(char *str) > { > + size_t size; > + int mode_idx; > + > if (!str) > return -EINVAL; > > - if (!strcmp(str, "disable")) { > - cppc_load = 0; > - pr_info("driver is explicitly disabled\n"); > - } else if (!strcmp(str, "passive")) > - cppc_load = 1; > + size = strlen(str); > + mode_idx = get_mode_idx_from_str(str, size); > > - return 0; > + if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) { > + cppc_state = mode_idx; > + if (cppc_state == AMD_PSTATE_DISABLE) > + pr_info("driver is explicitly disabled\n"); > + > + return 0; > + } > + > + return -EINVAL; > } > early_param("amd_pstate", amd_pstate_param); > > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h > index 1c4b8659f171..922d05a13902 100644 > --- a/include/linux/amd-pstate.h > +++ b/include/linux/amd-pstate.h > @@ -74,4 +74,33 @@ struct amd_cpudata { > bool boost_supported; > }; > > +/** > + * enum amd_pstate_mode - driver working mode of amd pstate > + */ > + > +enum amd_pstate_mode { > + /** @AMD_PSTATE_DISABLE: Driver mode is disabled */ > + AMD_PSTATE_DISABLE = 0, > + > + /** @AMD_PSTATE_PASSIVE: Drier mode is passive mode */
s/Drier/Driver/
> + AMD_PSTATE_PASSIVE = 1, > + > + /** @AMD_PSTATE_ACTIVE: Driver mode is active mode */ > + AMD_PSTATE_ACTIVE = 2, > + > + /** @AMD_PSTATE_GUIDE: Driver mode is guided mode */ > + AMD_PSTATE_GUIDE = 3, > + > + /** @AMD_PSTATE_MAX */ > + AMD_PSTATE_MAX = 4, > +}; > + > +static const char * const amd_pstate_mode_string[] = { > + [AMD_PSTATE_DISABLE] = "disable", > + [AMD_PSTATE_PASSIVE] = "passive", > + [AMD_PSTATE_ACTIVE] = "active", > + [AMD_PSTATE_GUIDE] = "guide",
I get the intent here, but guided mode isn't actually part of the v8 series under review.
I think it should either be folded into the series or this patch should be split into two across the two patch-sets: 1) introduce the state machine (part of the EPP patch-set) 2) add guided mode support (part of the guided mode patch-set).
> + NULL, > +}; > + > #endif /* _LINUX_AMD_PSTATE_H */
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