Hi alan: 2011/1/1 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > On Fri, 31 Dec 2010, vichy wrote: > >> > 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? > > usb_hcd_giveback_urb calls usbmon_urb_complete. This is always true, > regardless of whether the URB times out. after tracing the source code, I found usb_hcd_giveback_urb will be called in ehci_urb_done when interrupt happen and that is the normal path. But what makes me confuse is when timeout happen such as wait_for_completion_timeout in usb_start_wait_urb, which function will call usb_hcd_giveback_urb and bring -2 to it originally I guess maybe the ehci_watchdog, but I think it is not, because the function has no idea of the time out parameter, right? BTW, under what circumstance the status of urb will be -150? I grep include/linux and didn't find amy error number which is -150. 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
