| Message ID | 7572899.CfQ69SdO4W@aspire.rjw.lan (mailing list archive) |
|---|---|
| State | Deferred |
| Headers | show |
On Mon, Sep 25, 2017 at 01:30:51AM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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 <rafael.j.wysocki@intel.com> > Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> > Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> > Tested-by: Johannes Stezenbach <js@sig21.net> > Tested-by: Rajat Jain <rajatja@google.com> Applied to for-next, thanks!
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)