Re: [PATCH v3 2/3] usb: xhci: implement device_suspend/device_resume entries

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, May 07, 2015 at 10:18:15AM +0800, Lu Baolu wrote:
> This patch implements device_suspend/device_resume entries for xHC driver.
> device_suspend will be called when a USB device is about to suspend. It
> will issue a stop endpoint command for each endpoint in this device. The
> Suspend(SP) bit in the command TRB will set which will give xHC a hint
> about the suspend. device_resume will be called when a USB device is just
> resumed. It will ring doorbells of all endpoint unconditionally. XHC may
> use these suspend/resume hints to optimize its operation.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/usb/host/xhci-hub.c |  2 +-
>  drivers/usb/host/xhci.c     | 40 ++++++++++++++++++++++++++++++++++++++++
>  drivers/usb/host/xhci.h     | 11 +++++++++++
>  3 files changed, 52 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 0827d7c..a83e82e 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -266,7 +266,7 @@ int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
>   * to complete.
>   * suspend will set to 1, if suspend bit need to set in command.
>   */
> -static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
> +int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
>  {
>  	struct xhci_virt_device *virt_dev;
>  	struct xhci_command *cmd;
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index ec8ac16..6b61833 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -4680,6 +4680,40 @@ int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd,
>  		return ret;
>  	return 0;
>  }
> +
> +/*
> + * xHCI compatible host controller driver expects to be notified prior to
> + * selectively suspending a device. xHCI hcd could optimize the endpoint
> + * cache for power saving purpose. Refer to 4.15.1.1 of xHCI 1.1.
> + */
> +void xhci_device_suspend(struct usb_hcd *hcd,
> +			struct usb_device *udev, pm_message_t msg)

You never use the 'msg' field, so please remove it from the callback.

> +{
> +	struct xhci_hcd	*xhci;
> +
> +	xhci = hcd_to_xhci(hcd);
> +	if (!xhci || !xhci->devs[udev->slot_id])
> +		return;
> +
> +	xhci_stop_device(xhci, udev->slot_id, 1);
> +}
> +
> +/*
> + * xHCI compatible host controller driver expects to be notified after a
> + * USB device is resumed. xHCI hcd could optimize the endpoint cache
> + * to reduce the latency. Refer to 4.15.1.1 of xHCI 1.1.
> + */
> +void xhci_device_resume(struct usb_hcd *hcd,
> +			struct usb_device *udev, pm_message_t msg)

Same here.