[PATCH v9 4/4] USB / PM: Allow USB devices to remain runtime-suspended when sleeping

From: Tomeu Vizoso
Date: Mon Oct 05 2015 - 10:51:03 EST


Have dev_pm_ops.prepare return 1 for USB devices and ports so that USB
devices can remain runtime-suspended when the system goes to a sleep
state, if their wakeup state is correct and they have runtime PM enabled.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
---


drivers/usb/core/port.c | 6 ++++++
drivers/usb/core/usb.c | 11 ++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 210618319f10..f49707d73b5a 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -168,12 +168,18 @@ static int usb_port_runtime_suspend(struct device *dev)

return retval;
}
+
+static int usb_port_prepare(struct device *dev)
+{
+ return 1;
+}
#endif

static const struct dev_pm_ops usb_port_pm_ops = {
#ifdef CONFIG_PM
.runtime_suspend = usb_port_runtime_suspend,
.runtime_resume = usb_port_runtime_resume,
+ .prepare = usb_port_prepare,
#endif
};

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 8d5b2f4113cd..cf4dde11db1c 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -316,7 +316,16 @@ static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)

static int usb_dev_prepare(struct device *dev)
{
- return 0; /* Implement eventually? */
+ struct usb_device *udev = to_usb_device(dev);
+
+ if (!pm_runtime_enabled(dev))
+ return 0;
+
+ /* Return 0 if the current wakeup setting is wrong, otherwise 1 */
+ if (udev->do_remote_wakeup != device_may_wakeup(dev))
+ return 0;
+
+ return 1;
}

static void usb_dev_complete(struct device *dev)
--
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/