NAME¶

usb_queue_reset_device - Reset a USB device from an atomic context

SYNOPSIS¶

ARGUMENTS¶

iface

DESCRIPTION¶

This function can be used to reset a USB device from an atomic context, where usb_reset_device won't work (as it blocks). Doing a reset via this method is functionally equivalent to calling usb_reset_device, except for the fact that it is delayed to a workqueue. This means that any drivers bound to other interfaces might be unbound, as well as users from usbfs in user space.

CORNER CASES¶

- Scheduling two resets at the same time from two different drivers attached to two different interfaces of the same device is possible; depending on how the driver attached to each interface handles -> pre_reset, the second reset might happen or not. - If a driver is unbound and it had a pending reset, the reset will be cancelled. - This function can be called during . probe or . disconnect times. On return from . disconnect, any pending resets will be cancelled. There is no no need to lock/unlock the reset_ws as schedule_work does its own.

NOTE¶

We don't do any reference count tracking because it is not needed. The lifecycle of the work_struct is tied to the usb_interface. Before destroying the interface we cancel the work_struct, so the fact that work_struct is queued and or running means the interface (and thus, the device) exist and are referenced.

COPYRIGHT¶