On Wed, 20 Jan 2010, Hársszegi Tibor wrote: > Hi, > > our company uses a FTDI_SIO based USB 2.0 printer. > This printer has "ill habits" so that sometimes it gets stuck and no longer replies to > usb_control_msg()-es. > We had a "fix" for this behaviour to change 2 USB related modules within the Linux kernel. > (Check attachment, those are for the OpenSuse 11.1 2.6.27.7-pae kernel). > > 1.) FTDI_SIO, we changed this to "overrule" the regular > usb_control_msg() with our own wrapper. Within this wrapper we counted within 60 second the number of unacked usb_control_msg()s and if that reached 10, we restarted the USB HUB owning our printer > (we had to kickstart the HUB instead of the printer as restarting the printer didn't help). By "kickstart", do you mean calling usb_kick_khubd()? That's very different from restarting the hub. Besides, if a hub is working correctly then calling usb_kick_khubd() won't do anything other than wake up the hub (if it was suspended). Like Greg said, first you should find the real cause of the problem. Using usbmon is the best approach. 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
