Since the USB ports of my notebook are drived by UHCI HCs on buses 1 and 2, then I infer that I don't need worry about the bluetooth services or webcam on buses 3 and 5. Thank you very much.. On Fri, Jul 24, 2009 at 5:37 PM, Alan Stern<stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 24 Jul 2009, cihan öztürk wrote: > >> Hi all, >> I am trying to test the maximum USB bandwidth that can be allocated to >> a class of USB devices. I am looking forward to removing all other USB >> devices on my system, so that I am sure that the Host Controller >> doesn't reserve any bandwith to other devices. > > You don't have to remove all the other USB devices on your system, only > the other USB devices attached to the same host controller. Different > host controllers are on separate buses and therefore have independent > bandwidth. > >> lsusb command outputs: >> Bus 005 Device 004: ID 05e1:0501 Syntek Semiconductor Co., Ltd WebCam, >> Chipset DC-1125 similar to 174f:a311 - Asus F2F, F2J, F3J, F3T, G1, Z53JA >> Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub >> Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub >> Bus 003 Device 002: ID 0b05:1712 ASUSTek Computer, Inc. BT-183 Bluetooth >> 2.0+EDR adapter >> Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub >> Bus 002 Device 002: ID 046d:c019 Logitech, Inc. Optical Tilt Wheel Mouse >> Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub >> Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub >> >> The mouse is easy to remove, but the other two devices are integrated >> to my notebook. I have searched the forums but could not find how to >> remove them from my system. I am also not sure if I do need to >> remove them, since they may not be reserved any bandwidth while they >> are not in use. The webcam on bus 5 is definely not in use, because >> I succesfully remove its driver(assuming it's driven by stkwebcam) >> from system. But even then it's still in lsusb list. >> But when I try to remove any bluetooth related drivers(ie. btusb), it >> gives the error "module in use". >> >> Also, lsmod |grep usb gives: >> btusb 11856 3 >> bluetooth 52740 11 sco,rfcomm,bnep,l2cap,btusb >> usbhid 24480 0 >> hid 42048 1 usbhid >> usbcore 159664 6 stkwebcam,btusb,usbhid,ehci_hcd,uhci_hcd >> >> Lastly, I observed the traffic at buses 3 and 5 with usbmon while >> communicating with my own devices on other buses, and generated >> output files for buses 3 and 5 were empty. Does that mean that no >> bandwidth was reserved for them by the HC, so that they don't interfere >> my USB tests? > > Not necessarily. usbmon displays information when a transfer begins > and when it ends, but not while it is in progress. There could be > long-running transfers in progress on buses 3 and 5, and you wouldn't > see them. But if the webcam was the only device on bus 5 and you > removed its driver then it couldn't be using any bandwidth. > > However, if your devices are all on other buses then you shouldn't care > how much bandwidth is being used on buses 3 and 5. > > 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
