Sure. Pushing it to the older kernels will definitely help. Thanks, Ravi On Sat, Apr 21, 2018 at 1:59 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, Apr 20, 2018 at 11:08:21AM -0700, Ravi Chandra Sadineni wrote: >> On chromebooks we depend on wakeup count to identify the wakeup source. >> But currently USB devices do not increment the wakeup count when they >> trigger the remote wake. This patch addresses the same. >> >> Resume condition is reported differently on USB 2.0 and USB 3.0 devices. >> >> On USB 2.0 devices, a wake capable device, if wake enabled, drives >> resume signal to indicate a remote wake (USB 2.0 spec section 7.1.7.7). >> The upstream facing port then sets C_PORT_SUSPEND bit and reports a >> port change event (USB 2.0 spec section 11.24.2.7.2.3). Thus if a port >> has resumed before driving the resume signal from the host and >> C_PORT_SUSPEND is set, then the device attached to the given port might >> be the reason for the last system wakeup. Increment the wakeup count for >> the same. >> >> On USB 3.0 devices, a function may signal that it wants to exit from device >> suspend by sending a Function Wake Device Notification to the host (USB3.0 >> spec section 8.5.6.4) Thus on receiving the Function Wake, increment the >> wakeup count. >> >> Signed-off-by: Ravi Chandra Sadineni <ravisadineni@xxxxxxxxxxxx> >> --- >> >> V5: Added the description of changes between different versions of patches. >> V4: Moved the wakeup count increment logic to the existing if which is >> safegaurded by hcd_root_hub_lock spinlock. >> V3: Added a gaurd to check if rh_registered is set before accessing >> root_hub pointer. >> V2: Fixed the build failure error due to uninitialized dev pointer. > > Is this needed in older kernels? Should I submit it to the stable > trees? > > thanks, > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
