HID: usbhid: improve handling of Clear-Halt and reset
This patch changes the way usbhid carries out Clear-Halt and reset. Currently, after a Clear-Halt on the interrupt-IN endpoint, the driver immediately restarts the interrupt URB, even if the Clear-Halt failed. This doesn't work out well when the reason for the failure was that the device was disconnected (when a low- or full-speed device is connected through a hub to an EHCI controller, transfer errors caused by disconnection are reported as stalls by the hub). Instead now the driver will attempt a reset after a failed Clear-Halt. The way resets are carried out is also changed. Now the driver will call usb_queue_reset_device() instead of calling usb_reset_device() directly. This avoids a deadlock that would arise when a device is unplugged: The hid_reset() routine runs as a workqueue item, a reset attempt after the device has been unplugged will fail, failure will cause usbhid to be unbound, and the disconnect routine will try to do cancel_work_sync(). The usb_queue_reset_device() implementation is carefully written to handle scenarios like this one properly. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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