From patchwork Mon Dec 19 02:16:24 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tobias Jakobi X-Patchwork-Id: 9479597 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7586860836 for ; Mon, 19 Dec 2016 02:17:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 655E928410 for ; Mon, 19 Dec 2016 02:17:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5A3342843E; Mon, 19 Dec 2016 02:17:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0C10A2843B for ; Mon, 19 Dec 2016 02:17:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762090AbcLSCRv (ORCPT ); Sun, 18 Dec 2016 21:17:51 -0500 Received: from smtp.math.uni-bielefeld.de ([129.70.45.10]:43820 "EHLO smtp.math.uni-bielefeld.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762086AbcLSCRu (ORCPT ); Sun, 18 Dec 2016 21:17:50 -0500 Received: from chidori.lan (unknown [5.146.177.82]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (Client did not present a certificate) by smtp.math.uni-bielefeld.de (Postfix) with ESMTPSA id 7641B5F85C; Mon, 19 Dec 2016 03:17:48 +0100 (CET) From: Tobias Jakobi To: linux-samsung-soc@vger.kernel.org Cc: linux-pm@vger.kernel.org, m.reichl@fivetechno.de, myungjoo.ham@gmail.com, cw00.choi@samsung.com, Tobias Jakobi Subject: [RFC v2 4/7] PM / devfreq: Suspend subsystem on system suspend/hibernate Date: Mon, 19 Dec 2016 03:16:24 +0100 Message-Id: <1482113787-28422-5-git-send-email-tjakobi@math.uni-bielefeld.de> X-Mailer: git-send-email 2.7.3 In-Reply-To: <1482113787-28422-1-git-send-email-tjakobi@math.uni-bielefeld.de> References: <1482113787-28422-1-git-send-email-tjakobi@math.uni-bielefeld.de> Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On the Exynos4412 SoC the DevFreq subsystem adjusts the frequency of the various internal busses and the corresponding voltages. E.g. the clock of the DMC (dynamic memory controller) bus together with the voltage of the MIF regulator are controlled by this. If DMC activity is low and DevFreq has set a lower OPP, the following can happen. The transition to the lower OPP has set a voltage V_low. If the system now is restarted or goes into a suspend/resume-cycle, the first-stage (BL0) bootloader takes over, which also initializes clocks to default values, say freq_0 for the DMC. Since the PMIC is an external component and not part of the SoC, the BL0 doesn't set any default voltages. The BL0 now hangs because the required voltage V_0 (corresponding to freq_0) is higher than the currently set one V_low. To fix this, we make sure to only go into suspend with a 'safe' DevFreq OPP selected. Signed-off-by: Tobias Jakobi --- drivers/base/power/main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 5a94dfa..9cd7e06 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include "../base.h" @@ -943,6 +944,7 @@ void dpm_resume(pm_message_t state) dpm_show_time(starttime, state, NULL); cpufreq_resume(); + devfreq_resume(); trace_suspend_resume(TPS("dpm_resume"), state.event, false); } @@ -1582,6 +1584,7 @@ int dpm_suspend(pm_message_t state) trace_suspend_resume(TPS("dpm_suspend"), state.event, true); might_sleep(); + devfreq_suspend(); cpufreq_suspend(); mutex_lock(&dpm_list_mtx);