On Tue, Jan 7, 2014 at 11:53 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Jan 07, 2014 at 11:35:50AM +0800, 沈光 wrote: >> On Tue, Jan 7, 2014 at 10:40 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> > On Tue, Jan 07, 2014 at 10:33:14AM +0800, 沈光 wrote: >> >> set hub->change_bits when we plug in a device which causes >> >> over-current condition, so that hub_events() will check it. >> > >> > Why? >> > >> > What does this solve? Is this a bug with existing devices that needs to >> > be backported to older kernels? >> > >> > thanks, >> > >> > greg k-h >> >> This is something that we found when we are doing compliance test with xHCI. >> If we enable CONFIG_USB_SUSPEND, and plug in a bad device which causes >> over-current condition to the root port, the hub->change_bits will not >> be set in current code in the function of hub_activate. > > Now that's something that should go in the changelog, don't you think? > > thanks, > > greg k-h Sure, I agree. I am sorry I didn't make it clear enough. And the reason why over-current can be detected if CONFIG_USB_SUSPEND is disabled, is that the interrupt pipe of the hub will report the change and set hub->event_bits, and then hub_events() will check what events happened. Thanks, Shen Guang -- 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
