From: Shilpasri G Bhat Date: Thu, 16 Jul 2015 08:04:22 +0000 (+0530) Subject: cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=3dd3ebe5bb3837aeac28a23f8f22b97cb84abab6;p=openwrt%2Fstaging%2Fblogic.git cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set 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 Reviewed-by: Preeti U Murthy Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 22f33ff2d77a..90b42938837e 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) static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; static bool rebooting, throttled, occ_reset; @@ -313,7 +312,7 @@ 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); @@ -335,14 +334,9 @@ 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"); }