Messages in this thread | | | Date | Fri, 08 May 2015 15:46:20 +0800 | From | "Lu, Baolu" <> | Subject | Re: [PATCH v3 2/3] usb: xhci: implement device_suspend/device_resume entries |
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On 05/08/2015 03:28 PM, Greg Kroah-Hartman wrote: > On Fri, May 08, 2015 at 09:23:40AM +0800, Lu, Baolu wrote: >> >> On 05/08/2015 04:47 AM, Greg Kroah-Hartman wrote: >>> 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. >> 'msg' could be used in another patch to determine the pm event types: >> 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. > We don't add "features" to kernel code that is not used when it is > added. We can always change function calls later as we do not have a > stable api at all.
Understand it now. I will remove 'msg' fields in v4 patch series.
> > thanks, > > greg k-h
Thank you. Baolu > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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