From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752768AbcLGKcL (ORCPT ); Wed, 7 Dec 2016 05:32:11 -0500 Received: from mail-pg0-f41.google.com ([74.125.83.41]:35245 "EHLO mail-pg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752549AbcLGKcJ (ORCPT ); Wed, 7 Dec 2016 05:32:09 -0500 From: Viresh Kumar To: Rafael Wysocki , Viresh Kumar , Nishanth Menon , Stephen Boyd Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Guittot , jonathanh@nvidia.com, swarren@nvidia.com, treding@nvidia.com, Viresh Kumar Subject: [PATCH] Revert "PM / OPP: Don't assume platform doesn't have regulators" Date: Wed, 7 Dec 2016 16:01:52 +0530 Message-Id: <1560e022c1584376cf5a55ed048e0b60485adf2b.1481106666.git.viresh.kumar@linaro.org> X-Mailer: git-send-email 2.7.1.410.g6faf27b Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This reverts commit ef3caabee9691386e6801ea92150e37277db9c7a. The commit was based on the assumption that a platform with voltages specified with individual OPPs, would have registered a regulator as well in order to do full DVFS. That assumption is broken by the Tegra124 platform. For Tegra124, the voltage is not scaled via a direct call to the regulator subsystem because the DFLL directly controls the I2C interface that controls the voltage. The DFLL essentially figures out the max frequency for a given voltage. So to run at a particular frequency, the DFLL continuously adjusts the voltage in a control loop fashion to get the desired frequency. Following are the logs from: NVIDIA Tegra124 Jetson TK1 cpufreq: cpufreq_online: CPU0: Running at unlisted freq: 696000 KHz cpu cpu0: dev_pm_opp_set_rate: Regulator not registered with OPP core cpufreq: __target_index: Failed to change cpu frequency: -22 ------------[ cut here ]------------ kernel BUG at drivers/cpufreq/cpufreq.c:1235! Fix these by reverting the offending commit. Signed-off-by: Viresh Kumar --- Rafael, you can simply drop the patch if that is easier for you. --- drivers/base/power/opp/core.c | 13 ------------- 1 file changed, 13 deletions(-) diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 7db672f632d9..6af371a55062 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -747,20 +747,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) /* Only frequency scaling */ if (!regulators) { - unsigned long u_volt = opp->supplies[0].u_volt; - rcu_read_unlock(); - - /* - * DT contained supply ratings? Consider platform failed to set - * regulators. - */ - if (unlikely(u_volt)) { - dev_err(dev, "%s: Regulator not registered with OPP core\n", - __func__); - return -EINVAL; - } - return _generic_set_opp_clk_only(dev, clk, old_freq, freq); } -- 2.7.1.410.g6faf27b