On 04/04/2014 10:04, Stanislaw Gruszka wrote: > On Thu, Apr 03, 2014 at 04:48:56PM +0200, Richard Genoud wrote: >> I've met an endless (or at least very long) loop if I power down the usb >> port on witch a usb wifi key is plugged. >> (Ok, it's not very smart to power down a usb port when a usb key is in >> used... but still, I think that should not lead to an endless loop). >> >> I have a lot of: >> ieee80211 phy1: rt2x00usb_vendor_request: Error - Vendor Request 0x07 failed for offset 0x0438 with error -71 >> >> (-71==-EPROTO) >> >> How to reproduce: >> - plug an usb wifi key >> - ip link set wlan0 up >> - hub-ctrl -b usb_bus -d usb_device -P usb_port -p 0 >> >> hub-ctrl source: https://github.com/codazoda/hub-ctrl.c/blob/master/hub-ctrl.c >> >> The following patch prevents the endless loop, but I'm really not sure >> that The Right Way To Do It (R) > > If device disappear, we should get -ENODEV status, why we get -EPROTO ? I trace it down, and the EPROTO status comes from ctx.status (returned from usb_start_wait_urb() in drivers/usb/core/message.c) And, in my case, the ctx.status is set to EPROTO in qtd_copy_status() ( drivers/usb/host/ehci-q.c ) in the code: } else if (token & QTD_STS_XACT) { /* timeout, bad CRC, wrong PID, etc */ ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n", urb->dev->devpath, usb_pipeendpoint(urb->pipe), usb_pipein(urb->pipe) ? "in" : "out"); status = -EPROTO; enabling this log, I get: atmel-ehci 700000.ehci: devpath 2.1 ep1in 3strikes atmel-ehci 700000.ehci: devpath 2.1 ep0in 3strikes atmel-ehci 700000.ehci: devpath 2.1 ep1in 3strikes atmel-ehci 700000.ehci: devpath 2.1 ep0in 3strikes ieee80211 phy0: rt2800usb_tx_sta_fifo_read_completed: Warning - TX status read failed -71 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
