hi Alan: 2014-05-23 22:34 GMT+08:00 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > On Fri, 23 May 2014, vichy wrote: > >> hi all: >> Sorry for not making my description more clearer. >> in ehci controller, >> 1. is it possible to know the period bandwidth in a frame from sys or >> other additional configuration? > > The information is available in debugfs, in > /sys/kernel/debug/usb/ehci/.../bandwidth. > >> 2. is it possible to know how many bits in SMASK and CMASK are >> assigned to 1 in a frame? > > Do you mean how bits in SMASK and CMASK are set to 1 in a QH or sITD? YES > The SMASK and CMASK values are provided in > /sys/kernel/debug/usb/ehci/.../periodic. > Below is the directory content under /sys/kernel/debug/usb And I cannot see ehci directory. My kernel version is Linux 2.6.38-8-generic. Should I recompile kernel with additional configuration? # ls /sys/kernel/debug/usb/ devices usbmon # appreciate your kind help -- 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
