Hi, Alan, I am sorry, I do not see why qh_completions() has anything to do with usb_disconnect(). Thanks, Julie. > -----Original Message----- > From: Alan Stern [mailto:stern@xxxxxxxxxxxxxxxxxxx] > Sent: Friday, June 12, 2009 11:12 AM > To: Julie Zhu > Cc: USB list > Subject: RE: periodic schedule enabled during usb_disconnect > > On Fri, 12 Jun 2009, Julie Zhu wrote: > > > > > Is this a bug? > > > > > > Probably not. The periodic schedule should be enabled as long as any > > > periodic URBs are queued. The fact that they are addressed to a > > device > > > which has been unplugged doesn't matter -- usb_disconnect() will > > unlink > > > the remaining URBs for the unplugged device quickly enough. > > > > > > Alan Stern > > > > > > > Well, it does happen, and printks show the path of periodic schedule > > disable/enable/disable. > > Sure. It happens, but it's not a bug. The same thing would happen if > you queued a bunch of interrupt URBs for a device and then unlinked the > first one, without unplugging anything. > > > Can you point me to where qh->qtd_list is > > updated? > > It is updated in qh_completions(). There are two widely separated > regions in the source code: > > list_for_each_safe (entry, tmp, &qh->qtd_list) { > struct ehci_qtd *qtd; > ... > qtd = list_entry (entry, struct ehci_qtd, qtd_list); > > and then much later: > > /* remove qtd; it's recycled after possible urb completion */ > list_del (&qtd->qtd_list); > > Alan Stern > This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. -- 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
