On Wed, 5 Mar 2014, Jagdish Gedia wrote: > Hi, > There is some inconsistency in remote wakeup functionality in my > custom board. so I want to wakeup the runtime suspended USB host > through interrupt. My USB device is connected to the board through USB > interface and some gpios. device will give interrupt on processor gpio > when it needs attention of USB host. What should i do so that i can > wakeup the usb host when i get interrupt from the device.
Have your gpio interrupt handler call pm_request_resume() for the host controller device. However, this may not do what you want. Since the root hub will remain suspended, the host controller will go back to low-power immediately after it is resumed. You really need to resume the USB device itself, not the host controller. > My idea was to apply power management related hooks from the interrupt > handler, but I am not getting the clear idea. > > My main doubt is, > Will this mechanism be efficient as remote wakeup functionality? That's a hard question to answer without measurements. But it shouldn't matter, because you probably won't get more than one wakeup per second, right? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
