Hi Tomeu,
On Fri, Apr 03, 2015 at 02:57:56PM +0200, Tomeu Vizoso wrote:
> Have dev_pm_ops.prepare return 1 for USB devices, interfaces, endpoints
> and ports so that USB devices can remain runtime-suspended when the
> system goes to a sleep state, if their wakeup state is correct.
>
> Also enable runtime PM for endpoints, which is another requirement for
> the above to work.
After patching I think the 4th unrelated subsystem with stubs for
prepare() I think it is pretty clear that this approach is not the right
one.
If your driver does not care about any children hanging off it there is
dev->ignore_children flag that either already does what you want, or
maybe needs adjusted to support your use case.
Thanks.
>
> Signed-off-by: Tomeu Vizoso <tomeu.viz...@collabora.com>
> ---
> drivers/usb/core/endpoint.c | 17 +++++++++++++++++
> drivers/usb/core/message.c | 16 ++++++++++++++++
> drivers/usb/core/port.c | 6 ++++++
> drivers/usb/core/usb.c | 8 +++++++-
> 4 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
> index 39a2402..7c82bb7 100644
> --- a/drivers/usb/core/endpoint.c
> +++ b/drivers/usb/core/endpoint.c
> @@ -160,6 +160,19 @@ static const struct attribute_group *ep_dev_groups[] = {
> NULL
> };
>
> +#ifdef CONFIG_PM
> +
> +static int usb_ep_device_prepare(struct device *dev)
> +{
> + return 1;
> +}
> +
> +static const struct dev_pm_ops usb_ep_device_pm_ops = {
> + .prepare = usb_ep_device_prepare,
> +};
> +
> +#endif /* CONFIG_PM */
> +
> static void ep_device_release(struct device *dev)
> {
> struct ep_device *ep_dev = to_ep_device(dev);
> @@ -170,6 +183,9 @@ static void ep_device_release(struct device *dev)
> struct device_type usb_ep_device_type = {
> .name = "usb_endpoint",
> .release = ep_device_release,
> +#ifdef CONFIG_PM
> + .pm = &usb_ep_device_pm_ops,
> +#endif
> };
>
> int usb_create_ep_devs(struct device *parent,
> @@ -197,6 +213,7 @@ int usb_create_ep_devs(struct device *parent,
> goto error_register;
>
> device_enable_async_suspend(&ep_dev->dev);
> + pm_runtime_enable(&ep_dev->dev);
> endpoint->ep_dev = ep_dev;
> return retval;
>
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index f368d20..9041aee 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -1589,10 +1589,26 @@ static int usb_if_uevent(struct device *dev, struct
> kobj_uevent_env *env)
> return 0;
> }
>
> +#ifdef CONFIG_PM
> +
> +static int usb_if_prepare(struct device *dev)
> +{
> + return 1;
> +}
> +
> +static const struct dev_pm_ops usb_if_pm_ops = {
> + .prepare = usb_if_prepare,
> +};
> +
> +#endif /* CONFIG_PM */
> +
> struct device_type usb_if_device_type = {
> .name = "usb_interface",
> .release = usb_release_interface,
> .uevent = usb_if_uevent,
> +#ifdef CONFIG_PM
> + .pm = &usb_if_pm_ops,
> +#endif
> };
>
> static struct usb_interface_assoc_descriptor *find_iad(struct usb_device
> *dev,
> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
> index 2106183..f49707d 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 8d5b2f4..3a55c91 100644
> --- a/drivers/usb/core/usb.c
> +++ b/drivers/usb/core/usb.c
> @@ -316,7 +316,13 @@ 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);
> +
> + /* 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)
> --
> 2.3.4
>
> --
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--
Dmitry
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