A device may need the controller up during suspend_noirq() or resume_noirq(). But if the controller is autosuspended, there is no way to wakeup it during suspend_noirq() or resume_noirq() because runtime pm is disabled at this time. The suspend() callback wakes up the controller, so it is available until its suspend_noirq() callback (pm_runtime_force_suspend()). During the resume, it's restored by resume_noirq() callback (pm_runtime_force_resume()). Then resume() callback enables autosuspend. So the controller is up during a little time slot in suspend and resume sequences even if it's not used. Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx> Acked-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Thomas Richard <thomas.richard@xxxxxxxxxxx> --- drivers/i2c/busses/i2c-omap.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 258839845b12..c767a6418962 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -1575,9 +1575,31 @@ static int omap_i2c_runtime_resume(struct device *dev) return 0; } +static int omap_i2c_suspend(struct device *dev) +{ + /* + * If the controller is autosuspended, there is no way to wakeup it once + * runtime pm is disabled (in suspend_late()). + * But a device may need the controller up during suspend_noirq() or + * resume_noirq(). + * Wakeup the controller while runtime pm is enabled, so it is available + * until its suspend_noirq(), and from resume_noirq(). + */ + return pm_runtime_resume_and_get(dev); +} + +static int omap_i2c_resume(struct device *dev) +{ + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + + return 0; +} + static const struct dev_pm_ops omap_i2c_pm_ops = { NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) + SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume) RUNTIME_PM_OPS(omap_i2c_runtime_suspend, omap_i2c_runtime_resume, NULL) }; -- 2.39.2