On Jul 21, 2013, at 8:11 PM, Alan Stern <st...@rowland.harvard.edu> wrote:
> On Sun, 21 Jul 2013, Nathan Hjelm wrote: > >> A little more detail about what is happening in this case. When the >> device gets disconnected the hotplug backend calls >> usbi_handle_disconnect which then �completes� (makes all outstanding >> transfers as failed) all in-flight transfers. The darwin backend then >> gets notification for the OS that transfer(s) have failed. This is >> tricky to deal with because the user may have: freed the transfer, >> released the device, etc. I think the best course of action is to >> leave the hotplug backend code in place and �complete" any >> outstanding transfers and then ignore the completion callback from >> the OS. I should have the patch ready later today or sometime >> tomorrow. > > Are you sure this is the best approach? IMO it would make more sense > to mark the device as gone when the disconnect notification is > received, but leave the transfers intact. They will soon fail all by > themselves, and the OS completion callbacks can be handled in the usual > way. After all the transfers are gone, then it will be safe to finish > the disconnection procedure. Thinking about it you are correct. It would be simple enough: ref the device in darwin_submit_transfer and deref the device when the completion callback happens. My real concern is what happens in Linux when a device disconnects? Do you get notification for each pending transaction? If not I can add a capability flag to indicate that the OS will handle completion of the cancelled transfers. -Nathan ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
