> -----Original Message----- > From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- > owner@xxxxxxxxxxxxxxx] On Behalf Of Sarah Sharp > Sent: Saturday, August 06, 2011 1:06 AM > To: Xu, Andiry > Cc: linux-usb@xxxxxxxxxxxxxxx > Subject: Re: [RFC 3/3] xhci: Remove TDs from TD lists when URBs are > canceled. > > On Fri, Aug 05, 2011 at 01:45:39PM +0800, Xu, Andiry wrote: > > > @@ -1252,6 +1252,13 @@ int xhci_urb_dequeue(struct usb_hcd *hcd, > > struct > > > urb *urb, int status) > > > if (temp == 0xffffffff || (xhci->xhc_state & XHCI_STATE_HALTED)) > > > { > > > xhci_dbg(xhci, "HW died, freeing TD.\n"); > > > urb_priv = urb->hcpriv; > > > + for (i = urb_priv->td_cnt; i < urb_priv->length; i++) { > > > + td = urb_priv->td[i]; > > > + if (!list_empty(&td->td_list)) > > > + list_del_init(&td->td_list); > > > + if (!list_empty(&td->cancelled_td_list)) > > > + list_del_init(&td->cancelled_td_list); > > > + } > > > > > > > Can we just add the urb's unprocessed tds to cancelled_td_list here, > and > > let the watchdog function give it back and free urb_priv later? I > think > > that complies with the normal path we dequeue a urb. > > The interesting thing is that the watchdog timer might not actually be > running when this code is hit. The conditional also checks to see if > the host controller has been physically removed from the ExpressCard > slot by checking temp. There's no guarantee that a command will be > running when the host is removed, so we can't count on the watchdog > timer removing the URB from the TD lists and giving it back to the > driver. > > I've even submitted a patch to make sure the xHCI driver doesn't submit > commands to a halted host controller, so we'll never submit a stop > endpoint command when the host is removed, and the watchdog timer will > never run. So I think the code to remove the TDs is necessary. > I see, thanks for the explanation. Thanks, Andiry -- 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
