Matthew Dharm wrote: > My previous observations are that URBs for disconnected devices are > completed very quickly (i.e. <1 sec). There has been some suggestion that > there might be a case where this is not true... I have not seen it, and > would like to know where it might exist. > > And yes, this does apply to CBI devices. I believe the interrupt > completion gets called with a status to indicate the device is gone. > Again, that's what I observed last time I tested this behavior....
Yes: modulo bugs in the host controller driver. If the device neither transfers nor NAKs, there's a problem. - Dave > Matt > > On Fri, Jul 05, 2002 at 07:22:01AM +0200, Manfred Spraul wrote: > >>David Brownell wrote: >> >>>Matthew Dharm wrote: >>> >>> >>>>Blocking until all URBs complete is (effectively) what we do now... >>>> >>>>But this is an important question.. do those URBs get 'completed' or >>>>not at >>>>disconnection? Better question: should they? >>> >>> >>>Please explain your question a little better. I just >>>said they'll complete via unlink or transfer failure. >>>What's the issue? >>> >> >>The usb-storage driver submits an urb and waits for a reply from the >>hardware. If the user pulls out the cable, _disconnect() is called. The >>disconnect handler must wait until the currently processed request has >>finished. >> >>Right now it just waits on the request semaphore, without calling >>usb_unlink_urb(). >>Question: Is it guaranteed that the hcd will complete the urb within >>unnoticable time (< 1 sec or so) after the cable is pulled out. >> >>If the complete handler is not called immediately, then the user would >>notice a hang (20 seconds, until scsi midlayer timeout). The fix is >>obvious: call usb_unlink_urb() on the pending urb. >> >>-- >> Manfred > > ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Bringing you mounds of caffeinated joy. http://thinkgeek.com/sf _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
