From patchwork Fri Nov 29 04:15:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Viresh Kumar X-Patchwork-Id: 21856 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-ob0-f199.google.com (mail-ob0-f199.google.com [209.85.214.199]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id B5E4B23FD2 for ; Fri, 29 Nov 2013 04:17:43 +0000 (UTC) Received: by mail-ob0-f199.google.com with SMTP id gq1sf29713965obb.6 for ; Thu, 28 Nov 2013 20:17:42 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:x-original-sender:x-original-authentication-results :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-unsubscribe; bh=DvG1g/eMreiinV1VmJoc7W2LwIuWXBLB7u2mGlY28EA=; b=nMMb8rpmAD6H4zMhA6JsKatS5h8bCeHjMHkpuTBNoide9JHOYVdTdLHLpSPixl+oB7 yl8PtnKeHHUMqEc7w/+I965T6lWPEn/VlMa8uFXsvKx7dSUfMwZAfoymKLcbPzzkYqE0 43uWzkvhDO58rakV4inxdNJuGdJKeRWHCdtdc3hAEoYtK3+WUzxF+3Q7O0MFM+rnbbLz oVekaxmZ0y7PUDR6Tr5QU34bGSwWSKwvSbOb+FJAo8LQR+GQXoXpJzeILxw80CvMxxjL tm2atCBZi7geZZGJ6v4U5ronWE5y01waarXSm2kLUn9n8kuHLfaArl4fJmVgu5vUWntd 1/yw== X-Gm-Message-State: ALoCoQlXpaIvPRBDVEL4AQyopXl6oaAWHLu4zfh0KAB910BUJV8sLOj7seha0h97irAiZCudOYWD X-Received: by 10.43.152.19 with SMTP id ku19mr14691725icc.24.1385698662517; Thu, 28 Nov 2013 20:17:42 -0800 (PST) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.49.3.106 with SMTP id b10ls3494574qeb.40.gmail; Thu, 28 Nov 2013 20:17:42 -0800 (PST) X-Received: by 10.58.233.98 with SMTP id tv2mr41322815vec.11.1385698662382; Thu, 28 Nov 2013 20:17:42 -0800 (PST) Received: from mail-vc0-f172.google.com (mail-vc0-f172.google.com [209.85.220.172]) by mx.google.com with ESMTPS id on2si24087964vcb.15.2013.11.28.20.17.42 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 28 Nov 2013 20:17:42 -0800 (PST) Received-SPF: neutral (google.com: 209.85.220.172 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.220.172; Received: by mail-vc0-f172.google.com with SMTP id hz11so6196361vcb.17 for ; Thu, 28 Nov 2013 20:17:42 -0800 (PST) X-Received: by 10.220.11.7 with SMTP id r7mr41218984vcr.12.1385698662290; Thu, 28 Nov 2013 20:17:42 -0800 (PST) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.220.174.196 with SMTP id u4csp59483vcz; Thu, 28 Nov 2013 20:17:41 -0800 (PST) X-Received: by 10.66.149.37 with SMTP id tx5mr11081696pab.81.1385698661110; Thu, 28 Nov 2013 20:17:41 -0800 (PST) Received: from mail-pb0-f51.google.com (mail-pb0-f51.google.com [209.85.160.51]) by mx.google.com with ESMTPS id fn9si5706215pab.0.2013.11.28.20.17.40 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 28 Nov 2013 20:17:41 -0800 (PST) Received-SPF: neutral (google.com: 209.85.160.51 is neither permitted nor denied by best guess record for domain of viresh.kumar@linaro.org) client-ip=209.85.160.51; Received: by mail-pb0-f51.google.com with SMTP id up15so13615039pbc.24 for ; Thu, 28 Nov 2013 20:17:40 -0800 (PST) X-Received: by 10.66.255.39 with SMTP id an7mr49839491pad.7.1385698660551; Thu, 28 Nov 2013 20:17:40 -0800 (PST) Received: from localhost ([122.167.133.207]) by mx.google.com with ESMTPSA id om6sm9053825pbc.43.2013.11.28.20.17.35 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 28 Nov 2013 20:17:39 -0800 (PST) From: Viresh Kumar To: rjw@rjwysocki.net Cc: linaro-kernel@lists.linaro.org, patches@linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, nm@ti.com, ceh@ti.com, Viresh Kumar Subject: [PATCH V3 1/2] cpufreq: Make sure CPU is running on a freq from freq-table Date: Fri, 29 Nov 2013 09:45:26 +0530 Message-Id: <0596aca2267741a8be74db4d19a191c417779629.1385698209.git.viresh.kumar@linaro.org> X-Mailer: git-send-email 1.7.12.rc2.18.g61b472e X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: viresh.kumar@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.220.172 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , Sometimes boot loaders set CPU frequency to a value outside of frequency table present with cpufreq core. In such cases CPU might be unstable if it has to run on that frequency for long duration of time and so its better to set it to a frequency which is specified in freq-table. This also makes cpufreq stats inconsistent as cpufreq-stats would fail to register because current frequency of CPU isn't found in freq-table. Because we don't want this change to effect boot process badly, we go for the next freq which is >= policy->cur ('cur' must be set by now, otherwise we will end up setting freq to lowest of the table as 'cur' is initialized to zero). In case current frequency doesn't match any frequency from freq-table, we throw warnings to user, so that user can get this fixed in their bootloaders or freq-tables. On some systems we can't really say what frequency we're running at the moment and so for these we have added another flag: CPUFREQ_SKIP_INITIAL_FREQ_CHECK. Reported-by: Carlos Hernandez Reported-and-tested-by: Nishanth Menon Signed-off-by: Viresh Kumar --- V2->V3: - Minor cleanups suggested by Rafael - New patch: 2/2 (cpufreq: Mark x86 drivers with CPUFREQ_SKIP_INITIAL_FREQ_CHECK flag) - Rebased on PM/bleeding-edge drivers/cpufreq/cpufreq.c | 40 ++++++++++++++++++++++++++++++++++++++++ drivers/cpufreq/freq_table.c | 22 ++++++++++++++++++++++ include/linux/cpufreq.h | 11 +++++++++++ 3 files changed, 73 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 606224a..f13320a 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1042,6 +1042,46 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, } } + /* + * Sometimes boot loaders set CPU frequency to a value outside of + * frequency table present with cpufreq core. In such cases CPU might be + * unstable if it has to run on that frequency for long duration of time + * and so its better to set it to a frequency which is specified in + * freq-table. This also makes cpufreq stats inconsistent as + * cpufreq-stats would fail to register because current frequency of CPU + * isn't found in freq-table. + * + * Because we don't want this change to effect boot process badly, we go + * for the next freq which is >= policy->cur ('cur' must be set by now, + * otherwise we will end up setting freq to lowest of the table as 'cur' + * is initialized to zero). + * + * We are passing target-freq as "policy->cur - 1" otherwise + * __cpufreq_driver_target() would simply fail, as policy->cur will be + * equal to target-freq. + */ + if (!(cpufreq_driver->flags & CPUFREQ_SKIP_INITIAL_FREQ_CHECK) + && has_target()) { + /* Are we running at unknown frequency ? */ + ret = cpufreq_frequency_table_get_index(policy, policy->cur); + if (ret == -EINVAL) { + /* Warn user and fix it */ + pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", + __func__, policy->cpu, policy->cur); + ret = __cpufreq_driver_target(policy, policy->cur - 1, + CPUFREQ_RELATION_L); + + /* + * Reaching here after boot in a few seconds may not + * mean that system will remain stable at "unknown" + * frequency for longer duration. Hence, a BUG_ON(). + */ + BUG_ON(ret); + pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", + __func__, policy->cpu, policy->cur); + } + } + /* related cpus should atleast have policy->cpus */ cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c index 3458d27..a8ac042 100644 --- a/drivers/cpufreq/freq_table.c +++ b/drivers/cpufreq/freq_table.c @@ -178,7 +178,29 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy, } EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target); +int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy, + unsigned int freq) +{ + struct cpufreq_frequency_table *table; + int i; + + table = cpufreq_frequency_get_table(policy->cpu); + if (unlikely(!table)) { + pr_debug("%s: Unable to find frequency table\n", __func__); + return -ENOENT; + } + + for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { + if (table[i].frequency == freq) + return i; + } + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index); + static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table); + /** * show_available_freqs - show available frequencies for the specified CPU */ diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index ee5fe9d..03174ab 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -252,6 +252,15 @@ struct cpufreq_driver { */ #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4) +/* + * Set by drivers which don't want cpufreq core to check if CPU is running at a + * frequency present in freq-table exposed by the driver. For other drivers if + * CPU is found running at an out of table freq, we will try to set it to a freq + * from the table. And if that fails, we will stop further boot process by + * issuing a BUG_ON(). + */ +#define CPUFREQ_SKIP_INITIAL_FREQ_CHECK (1 << 5) + int cpufreq_register_driver(struct cpufreq_driver *driver_data); int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); @@ -447,6 +456,8 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation, unsigned int *index); +int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy, + unsigned int freq); void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy); ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);