On Fri, 10 Jan 2014, Venkatesh Murthy, HemanthX wrote: > Yes agree, but I think the multiple loops can be avoided. With the > below change in hub_port_wait_reset around 5 secs is saved for > disconnect detection. > > @@ -2545,15 +2546,15 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1, > port1, warm ? "warm " : "", delay); > } > > - if ((portstatus & USB_PORT_STAT_RESET)) > - return -EBUSY; > + /* Device went away? */ > + if (!(portstatus & USB_PORT_STAT_CONNECTION)) > + return -ENOTCONN; I don't think this is appropriate. If USB_PORT_STAT_RESET is still on then the reset hasn't finished yet. The port hardware can't tell whether or not a device is connected while it is driving a reset signal. (Well, maybe it can tell when the port is running at SuperSpeed, but it can't tell at lower speeds.) Therefore it is important not to test USB_PORT_STAT_CONNECTION until after you have tested USB_PORT_STAT_RESET. 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
