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. 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
