From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [RFT][PATCH v3 3/3] PM / i2c: designware: Clean up system sleep handling Date: Wed, 06 Sep 2017 01:48:50 +0200 Message-ID: <2320454.WkIRgD8XIu@aspire.rjw.lan> References: <3023226.l5IfJK6GIc@aspire.rjw.lan> <3958866.l2qnKDbinI@aspire.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <3958866.l2qnKDbinI@aspire.rjw.lan> Sender: linux-pm-owner@vger.kernel.org To: linux-pm@vger.kernel.org, linux-i2c@vger.kernel.org Cc: Wolfram Sang , 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 List-Id: linux-acpi@vger.kernel.org From: Rafael J. Wysocki After commit a23318feeff6 (i2c: designware: Fix system suspend) the i2c-designware-platdrv driver always resumes the device in its system sleep ->suspend callback which isn't particularly nice, even though it is technically correct. 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 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. Overrides: a23318feeff6 (i2c: designware: Fix system suspend) Signed-off-by: Rafael J. Wysocki --- -> 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. v2 -> v3: Keep the ->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. --- 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 @@ -451,14 +451,21 @@ 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 platform_device *pdev = to_platform_device(dev); struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); + 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; } @@ -467,27 +474,27 @@ static int dw_i2c_plat_resume(struct dev struct platform_device *pdev = to_platform_device(dev); struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); + 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)