From: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
To: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org
Cc: rjw@rjwysocki.net, viresh.kumar@linaro.org,
preeti@linux.vnet.ibm.com, linux-pm@vger.kernel.org,
Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Subject: [PATCH v3 5/6] cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set
Date: Mon, 4 May 2015 14:24:11 +0530 [thread overview]
Message-ID: <1430729652-14813-6-git-send-email-shilpa.bhat@linux.vnet.ibm.com> (raw)
In-Reply-To: <1430729652-14813-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com>
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");
}
--
1.9.3
next prev parent reply other threads:[~2015-05-04 9:01 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-04 8:54 [PATCH v3 0/6] powernv: cpufreq: Report frequency throttle by OCC Shilpasri G Bhat
2015-05-04 8:54 ` [PATCH v3 1/6] cpufreq: poowernv: Handle throttling due to Pmax capping at chip level Shilpasri G Bhat
2015-05-05 3:51 ` Preeti U Murthy
2015-05-05 6:06 ` Shilpasri G Bhat
2015-05-05 8:38 ` Preeti U Murthy
2015-05-07 10:35 ` Shilpasri G Bhat
2015-05-07 12:15 ` Preeti U Murthy
2015-05-04 8:54 ` [PATCH v3 2/6] powerpc/powernv: Add definition of OPAL_MSG_OCC message type Shilpasri G Bhat
2015-05-04 8:54 ` [PATCH v3 3/6] cpufreq: powernv: Register for OCC related opal_message notification Shilpasri G Bhat
2015-05-05 3:42 ` Preeti U Murthy
2015-05-04 8:54 ` [PATCH v3 4/6] cpufreq: powernv: Call throttle_check() on receiving OCC_THROTTLE Shilpasri G Bhat
2015-05-05 4:00 ` Preeti U Murthy
2015-05-05 6:33 ` Shilpasri G Bhat
2015-05-05 8:41 ` Preeti U Murthy
2015-05-07 12:19 ` Preeti U Murthy
2015-05-07 20:59 ` Rafael J. Wysocki
2015-05-08 3:46 ` Preeti U Murthy
2015-05-08 14:11 ` Rafael J. Wysocki
2015-05-04 8:54 ` Shilpasri G Bhat [this message]
2015-05-05 3:46 ` [PATCH v3 5/6] cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set Preeti U Murthy
2015-05-04 8:54 ` [PATCH v3 6/6] cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling Shilpasri G Bhat
2015-05-05 9:39 ` Preeti U Murthy
2015-05-08 5:12 ` [PATCH v3 0/6] powernv: cpufreq: Report frequency throttle by OCC Viresh Kumar
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