[PATCH v4 5/6] cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set
From: Shilpasri G Bhat <hidden>
Date: 2015-07-13 14:12:24
Also in:
linux-pm, lkml
Subsystem:
cpu frequency scaling framework, the rest · Maintainers:
"Rafael J. Wysocki", Viresh Kumar, Linus Torvalds
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 <redacted> Reviewed-by: Preeti U Murthy <redacted> --- No changes from v3 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 f2da30a..d6d7e68 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"); }
--
1.9.3