On Fri, May 08, 2015 at 09:23:40AM +0800, Lu, Baolu wrote:
We don't add "features" to kernel code that is not used when it is
On 05/08/2015 04:47 AM, Greg Kroah-Hartman wrote:
On Thu, May 07, 2015 at 10:18:15AM +0800, Lu Baolu wrote:'msg' could be used in another patch to determine the pm event types:
This patch implements device_suspend/device_resume entries for xHC driver.You never use the 'msg' field, so please remove it from the callback.
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@xxxxxxxxxxxxxxx>
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
@@ -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
@@ -4680,6 +4680,40 @@ int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd,
+ * 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 22.214.171.124 of xHCI 1.1.
+void xhci_device_suspend(struct usb_hcd *hcd,
+ struct usb_device *udev, pm_message_t msg)
auto-suspend or system suspend. I didn't bring up that patch together
with this patch series because 1) that's part of xhci 1.1 features, and
2) it's still not tested yet.
added. We can always change function calls later as we do not have a
stable api at all.
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