Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752744AbbEDJBY (ORCPT ); Mon, 4 May 2015 05:01:24 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:55317 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752656AbbEDJAf (ORCPT ); Mon, 4 May 2015 05:00:35 -0400 From: Shilpasri G Bhat 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 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 Message-Id: <1430729652-14813-6-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1430729652-14813-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> References: <1430729652-14813-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15050409-1618-0000-0000-00000206B17E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2219 Lines: 63 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 --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/