From patchwork Sun Sep 24 23:30:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 9968919 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 71A416038E for ; Sun, 24 Sep 2017 23:41:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6330628C00 for ; Sun, 24 Sep 2017 23:41:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 57EE228C0D; Sun, 24 Sep 2017 23:41:31 +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 4416E28C04 for ; Sun, 24 Sep 2017 23:41:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932272AbdIXXkp (ORCPT ); Sun, 24 Sep 2017 19:40:45 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:52647 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753545AbdIXXkm (ORCPT ); Sun, 24 Sep 2017 19:40:42 -0400 Received: from 79.184.252.54.ipv4.supernova.orange.pl (79.184.252.54) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.82) id e640f15b5aba28c8; Mon, 25 Sep 2017 01:40:40 +0200 From: "Rafael J. Wysocki" To: linux-pm@vger.kernel.org, Wolfram Sang Cc: linux-i2c@vger.kernel.org, linux-acpi@vger.kernel.org, Kevin Hilman , Jarkko Nikula , Andy Shevchenko , Mika Westerberg , Jisheng Zhang , John Stultz , Guodong Xu , Sumit Semwal , Haojian Zhuang , Johannes Stezenbach , Ulf Hansson , Lee Jones , Rajat Jain Subject: [PATCH v4 3/3] PM: i2c-designware-platdrv: Suspend/resume at the late/early stages Date: Mon, 25 Sep 2017 01:30:51 +0200 Message-ID: <7572899.CfQ69SdO4W@aspire.rjw.lan> In-Reply-To: <65494652.vEfz4tCBDb@aspire.rjw.lan> References: <3023226.l5IfJK6GIc@aspire.rjw.lan> <3958866.l2qnKDbinI@aspire.rjw.lan> <65494652.vEfz4tCBDb@aspire.rjw.lan> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rafael J. Wysocki As reported by Rajat Jain, there are problems when ACPI operation region handlers or similar, called at the ->resume_early() time, for I2C client devices try to access an I2C controller that has already been suspended at that point. To avoid that, move the suspend/resume of i2c-designware-platdrv to the late/early stages, respectively. While at it, avoid resuming the device from runtime suspend in the driver's ->suspend callback which isn't particularly nice. [A better approach would be to make the driver track the PM state of the device so that it doesn't need to resume it in ->suspend, so implement it.] First, drop dw_i2c_plat_suspend() added by commit a23318feeff6 (i2c: designware: Fix system suspend) and rename dw_i2c_plat_runtime_suspend() back to dw_i2c_plat_suspend(). Second, point the driver's ->late_suspend and ->early_resume callbacks, rather than its ->suspend and ->resume callbacks, to dw_i2c_plat_suspend() and dw_i2c_plat_resume(), respectively, so that they are not executed in parallel with each other, for example if runtime resume of the device takes place during system suspend. Finally, add "suspended" and "skip_resume" flags to struct dw_i2c_dev and make dw_i2c_plat_suspend() and dw_i2c_plat_resume() use them to avoid suspending or resuming the device twice in a row and to avoid resuming a previously runtime-suspended device during system resume. Signed-off-by: Rafael J. Wysocki Tested-by: Jarkko Nikula Tested-by: Mika Westerberg Tested-by: Johannes Stezenbach Tested-by: Rajat Jain --- v3 ->v4: Modify changelog to mention the problem addressed by this patch, rebase on top of 4.14-rc1 and add Tested-by tags. v2 -> v3: Do not drop ->prepare and ->complete system sleep callbacks as direct_complete is still useful for helping to avoid resuming the parent of this device in the intel-lpss case. -> v2: Add the "suspended" flag, which is needed, because dw_i2c_plat_suspend() doesn't update the runtime PM status of the device, so dw_i2c_plat_resume() can't rely on this check during system resume. --- drivers/i2c/busses/i2c-designware-core.h | 2 + drivers/i2c/busses/i2c-designware-platdrv.c | 33 ++++++++++++++++------------ 2 files changed, 22 insertions(+), 13 deletions(-) Index: linux-pm/drivers/i2c/busses/i2c-designware-core.h =================================================================== --- linux-pm.orig/drivers/i2c/busses/i2c-designware-core.h +++ linux-pm/drivers/i2c/busses/i2c-designware-core.h @@ -280,6 +280,8 @@ struct dw_i2c_dev { int (*acquire_lock)(struct dw_i2c_dev *dev); void (*release_lock)(struct dw_i2c_dev *dev); bool pm_disabled; + bool suspended; + bool skip_resume; void (*disable)(struct dw_i2c_dev *dev); void (*disable_int)(struct dw_i2c_dev *dev); int (*init)(struct dw_i2c_dev *dev); Index: linux-pm/drivers/i2c/busses/i2c-designware-platdrv.c =================================================================== --- linux-pm.orig/drivers/i2c/busses/i2c-designware-platdrv.c +++ linux-pm/drivers/i2c/busses/i2c-designware-platdrv.c @@ -451,13 +451,20 @@ static void dw_i2c_plat_complete(struct #endif #ifdef CONFIG_PM -static int dw_i2c_plat_runtime_suspend(struct device *dev) +static int dw_i2c_plat_suspend(struct device *dev) { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + if (i_dev->suspended) { + i_dev->skip_resume = true; + return 0; + } + i_dev->disable(i_dev); i2c_dw_plat_prepare_clk(i_dev, false); + i_dev->suspended = true; + return 0; } @@ -465,27 +472,27 @@ static int dw_i2c_plat_resume(struct dev { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + if (!i_dev->suspended) + return 0; + + if (i_dev->skip_resume) { + i_dev->skip_resume = false; + return 0; + } + i2c_dw_plat_prepare_clk(i_dev, true); i_dev->init(i_dev); - return 0; -} + i_dev->suspended = false; -#ifdef CONFIG_PM_SLEEP -static int dw_i2c_plat_suspend(struct device *dev) -{ - pm_runtime_resume(dev); - return dw_i2c_plat_runtime_suspend(dev); + return 0; } -#endif static const struct dev_pm_ops dw_i2c_dev_pm_ops = { .prepare = dw_i2c_plat_prepare, .complete = dw_i2c_plat_complete, - SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) - SET_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend, - dw_i2c_plat_resume, - NULL) + SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) + SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) }; #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)