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authorShilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>2015-07-16 13:34:22 +0530
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-07-28 17:24:14 +0200
commit3dd3ebe5bb3837aeac28a23f8f22b97cb84abab6 (patch)
tree68e642218e15b901525d42fa0db0e9be3ecc5b4b /drivers/cpufreq
parent735366fc407755626058218fc8d0430735a669ac (diff)
downloadlinux-3dd3ebe5bb3837aeac28a23f8f22b97cb84abab6.tar.bz2
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 <shilpa.bhat@linux.vnet.ibm.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/powernv-cpufreq.c12
1 files changed, 3 insertions, 9 deletions
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");
}