Hi Cihan, On Friday 24 July 2009 08:44:55 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. > > 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? USB bandwidth is only reserved for interrupt and isochronous transfers. A device associated with no driver will not have any pending interrupt or isochronous URB, and will not cause any bandwidth reservation. Regards, Laurent Pinchart -- 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
