An usb device can initate a remote wakeup and bring the link out of suspend as dictated by the DEVICE_REMOTE_WAKEUP feature selector. To achieve this an interface can invoke gadget_wakeup op and wait for the device to come out of LPM. But the current polling based implementation fails if the host takes a long time to drive the resume signaling specially in high speed capable devices. Switching to an interrupt based approach is more robust and efficient. This can be leveraged by enabling link status change events and triggering a gadget resume when the link comes to active state. If the device is super-speed/super-speed-plus capable, individual interfaces can also be put into suspend state. An interface can be in function suspend state even when the device is not in suspend state. Function suspend state is retained throughout the device suspend entry and exit process. A function can be put to function suspend through FUNCTION_SUSPEND feature selector sent by the host. This setup packet also decides whether that function is capable of initiating a function remote wakeup. When the function sends a wakeup notification to the host the link must be first brought to a non-U0 state and then this notification is sent. This change adds the infrastructure needed to support the above functionalities. Elson Roy Serrao (5): usb: dwc3: Add remote wakeup handling usb: gadget: Add function wakeup support usb: dwc3: Add function suspend and function wakeup support usb: gadget: f_ecm: Add suspend/resume and remote wakeup support usb: gadget: f_ecm: Add function suspend and wakeup support drivers/usb/dwc3/core.h | 5 ++ drivers/usb/dwc3/ep0.c | 16 +++--- drivers/usb/dwc3/gadget.c | 99 +++++++++++++++++++++++++++++++++-- drivers/usb/gadget/composite.c | 32 +++++++++++ drivers/usb/gadget/function/f_ecm.c | 67 ++++++++++++++++++++++++ drivers/usb/gadget/function/u_ether.c | 98 ++++++++++++++++++++++++++++++++++ drivers/usb/gadget/function/u_ether.h | 6 +++ drivers/usb/gadget/udc/core.c | 9 ++++ include/linux/usb/composite.h | 1 + include/linux/usb/gadget.h | 2 + 10 files changed, 324 insertions(+), 11 deletions(-) -- 2.7.4
