On Mon, 24 May 2010, Grant wrote: > >> >> What function does the USB Interrupt Threshold Control > >> >> value have? > >> > > >> > See the EHCI spec. Basically, it affects how long the > >> > hardware waits before reporting interrupts. Longer waits > >> > mean slower response times and worse throughput. Leave it > >> > alone. > >> > >> Can the value be read? > > > > Yes. > > Can you tell me how to read it? Yes, I can. :-) And to answer your next request: You need to be running a kernel that was built with CONFIG_USB_DEBUG enabled. Mount a debugfs filesystem and go to the correct subdirectory: mount -t debugfs none /sys/kernel/debug cd /sys/kernel/debug/usb/ehci/... where the "..." is the name corresponding to the EHCI controller you're interested in. Once in that directory, read the "registers" file. The "ithresh" number is the Interrupt Threshold Control value. 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
