On Fri, 19 May 2017, Kai-Heng Feng wrote: > Hi, > > This issue happens on Carrizo AMD laptops, only EHCI is affected, XHCI > works fine on the same machine. > > I can see lots of USB wakeup and resume messages showed every two seconds. > Plug USB devices to the EHCI port does not change anything. > > dmesg with ehci-hcd, ehci-pci and usbcore dynamic debug enabled is attached: > > [ 88.556535] ehci-pci 0000:00:13.0: hcd_pci_runtime_resume: 0 > [ 88.556563] usb usb2: usb auto-resume > [ 88.556588] hub 2-0:1.0: hub_resume > [ 88.556676] usb usb2-port1: status 0507 change 0000 > [ 88.556794] hub 2-0:1.0: state 7 ports 2 chg 0000 evt 0000 > [ 88.556862] usb 2-1: usb auto-resume > [ 88.624577] usb 2-1: Waited 0ms for CONNECT > [ 88.624585] usb 2-1: finish resume > [ 88.624838] hub 2-1:1.0: hub_resume > [ 88.624964] usb 2-1-port1: status 0507 change 0000 > [ 88.625085] usb 2-1-port2: status 0107 change 0000 > [ 88.625354] usb 2-1-port4: status 0507 change 0000 > [ 88.625403] hub 2-1:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 88.625605] usb 2-1.1: usb auto-resume > [ 88.692635] usb 2-1.1: Waited 0ms for CONNECT > [ 88.692640] usb 2-1.1: finish resume > [ 90.800874] usb 2-1.1: usb auto-suspend, wakeup 1 > [ 90.820326] hub 2-1:1.0: hub_suspend > [ 90.823161] usb 2-1: usb auto-suspend, wakeup 1 > [ 90.840362] hub 2-0:1.0: hub_suspend > [ 90.840399] usb usb2: bus auto-suspend, wakeup 1 > [ 90.860346] ehci-pci 0000:00:13.0: hcd_pci_runtime_suspend: 0 Your log shows that the 2-1.1 device is a USB2.0-CRW card reader, and it uses the rtsx_usb driver. This driver probes the reader every few seconds to see whether a card has been inserted (actually, it probes _twice_: once to see if an SD card is present and once to see if a MemoryStick card is present). Each probe (or pair of probes) causes a resume followed by a suspend. The way to prevent all those resumes and suspends -- if that's what you want to do -- is to disable autosuspend for the card reader. The best way to do this depends on your system, but echo on >/sys/bus/usb/devices/2-1.1/power/control should work. Alan Stern -- 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
