| Message ID | 1430729652-14813-6-git-send-email-shilpa.bhat@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Rafael Wysocki |
| Headers | show |
On 05/04/2015 02:24 PM, Shilpasri G Bhat wrote: > On a reset cycle of OCC, although the system retires from safe > frequency state the local pstate is not restored to Pmin or last > requested pstate. Now if the cpufreq governor initiates a pstate > change, the local pstate will be in Psafe and we will be reporting a > false positive when we are not throttled. > > So in powernv_cpufreq_throttle_check() remove the condition which > checks if local pstate is less than Pmin while checking for Psafe > frequency. If the cpus are forced to Psafe then PMSR.psafe_mode_active > bit will be set. So, when OCCs become active this bit will be cleared. > Let us just rely on this bit for reporting throttling. > > Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> > --- > drivers/cpufreq/powernv-cpufreq.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) > > diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c > index 9618813..0a59d5b 100644 > --- a/drivers/cpufreq/powernv-cpufreq.c > +++ b/drivers/cpufreq/powernv-cpufreq.c > @@ -39,7 +39,6 @@ > #define PMSR_PSAFE_ENABLE (1UL << 30) > #define PMSR_SPR_EM_DISABLE (1UL << 31) > #define PMSR_MAX(x) ((x >> 32) & 0xFF) > -#define PMSR_LP(x) ((x >> 48) & 0xFF) > #define OCC_RESET 0 > #define OCC_LOAD 1 > #define OCC_THROTTLE 2 > @@ -316,7 +315,7 @@ static void powernv_cpufreq_throttle_check(void *data) > { > unsigned int cpu = smp_processor_id(); > unsigned long pmsr; > - int pmsr_pmax, pmsr_lp, i; > + int pmsr_pmax, i; > > pmsr = get_pmspr(SPRN_PMSR); > > @@ -338,14 +337,9 @@ static void powernv_cpufreq_throttle_check(void *data) > chips[i].id, pmsr_pmax); > } > > - /* > - * Check for Psafe by reading LocalPstate > - * or check if Psafe_mode_active is set in PMSR. > - */ > + /* Check if Psafe_mode_active is set in PMSR. */ > next: > - pmsr_lp = (s8)PMSR_LP(pmsr); > - if ((pmsr_lp < powernv_pstate_info.min) || > - (pmsr & PMSR_PSAFE_ENABLE)) { > + if (pmsr & PMSR_PSAFE_ENABLE) { > throttled = true; > pr_info("Pstate set to safe frequency\n"); > } > Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 9618813..0a59d5b 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -39,7 +39,6 @@ #define PMSR_PSAFE_ENABLE (1UL << 30) #define PMSR_SPR_EM_DISABLE (1UL << 31) #define PMSR_MAX(x) ((x >> 32) & 0xFF) -#define PMSR_LP(x) ((x >> 48) & 0xFF) #define OCC_RESET 0 #define OCC_LOAD 1 #define OCC_THROTTLE 2 @@ -316,7 +315,7 @@ static void powernv_cpufreq_throttle_check(void *data) { unsigned int cpu = smp_processor_id(); unsigned long pmsr; - int pmsr_pmax, pmsr_lp, i; + int pmsr_pmax, i; pmsr = get_pmspr(SPRN_PMSR); @@ -338,14 +337,9 @@ static void powernv_cpufreq_throttle_check(void *data) chips[i].id, pmsr_pmax); } - /* - * Check for Psafe by reading LocalPstate - * or check if Psafe_mode_active is set in PMSR. - */ + /* Check if Psafe_mode_active is set in PMSR. */ next: - pmsr_lp = (s8)PMSR_LP(pmsr); - if ((pmsr_lp < powernv_pstate_info.min) || - (pmsr & PMSR_PSAFE_ENABLE)) { + if (pmsr & PMSR_PSAFE_ENABLE) { throttled = true; pr_info("Pstate set to safe frequency\n"); }
On a reset cycle of OCC, although the system retires from safe frequency state the local pstate is not restored to Pmin or last requested pstate. Now if the cpufreq governor initiates a pstate change, the local pstate will be in Psafe and we will be reporting a false positive when we are not throttled. So in powernv_cpufreq_throttle_check() remove the condition which checks if local pstate is less than Pmin while checking for Psafe frequency. If the cpus are forced to Psafe then PMSR.psafe_mode_active bit will be set. So, when OCCs become active this bit will be cleared. Let us just rely on this bit for reporting throttling. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> --- drivers/cpufreq/powernv-cpufreq.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)