Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752760AbbGMOMY (ORCPT ); Mon, 13 Jul 2015 10:12:24 -0400 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:35454 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752553AbbGMOL3 (ORCPT ); Mon, 13 Jul 2015 10:11:29 -0400 X-Helo: d23dlp01.au.ibm.com X-MailFrom: shilpa.bhat@linux.vnet.ibm.com X-RcptTo: linux-pm@vger.kernel.org From: Shilpasri G Bhat To: rjw@rjwysocki.net Cc: viresh.kumar@linaro.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Shilpasri G Bhat Subject: [PATCH v4 5/6] cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set Date: Mon, 13 Jul 2015 19:40:01 +0530 Message-Id: <1436796602-10228-6-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1436796602-10228-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> References: <1436796602-10228-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15071314-0021-0000-0000-00000186F823 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2353 Lines: 66 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 --- 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 -- 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/