hi all: 2010/11/22 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > On Mon, 22 Nov 2010, vichy wrote: > >> > Did you monitor the bus while running a test with a 10-second timeout? >> > Maybe comparing the results of the two tests will explain why the >> > timeout occurs. >> I found there is debugfs I can use to monitor each urb transaction. > > You should be more careful about the words you use. The usbmon > interface in debugfs monitors URBs. It does not monitor USB > transactions. > >> But I have one question? >> how could I combine output of dmesg and debugfs together? >> There is an timeout error message in usb driver and I want to combine >> dmesg together with urb traffic such that I can find out the urb of >> timeout happened. > > Make sure you have CONFIG_PRINTK_TIME enabled so that you get > high-resolution timestamps in the dmesg log. Although these timestamps > are not the same as the values used in usbmon, the difference between > them remains fixed. Therefore you can match up events between the two > logs. > > But you don't need a detailed comparison to find out which URB timed > out. You can tell by looking at the status code in the URB's > completion line; a timeout will set the status to -2. I can see -2 on the log of usbmon right now. And it seems from usbmon_urb_complete but if the timeout happen, which function call usbmon_urb_complete? appreciate your kind help :) vichy -- 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
