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
