hi: 2011/1/11 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > On Tue, 11 Jan 2011, loody wrote: > >> hi all: >> I found when debug compile option opened, usb driver will create ehci >> folder and 3 files, >> period, registers and async. >> They seems work like usbmon as explaind in ehci.txt in usb document. > > No, they do not work like usbmon. They contain internal debugging > information about the state of the EHCI controller and driver. > >> But when I try "cat async > /mnt/async.log" after plug in usb flash, >> the log shows nothing. >> but i did see the content when I "cat registers". >> Is there any setting or document I have to check first or the content >> of async will only show when I plug special device? > > The "async" file is non-empty only when there are control or bulk > transfers in progress. The "periodic" file is non-empty only when > there are interrupt or isochronous transfers in progress (roughly > speaking). Is it possible for capturing all the content of "async" to a file when I plug in some mass storage device such that I can analyze the qhs. Sincerely, miloody -- 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
