USB: cdc-wdm: don't enable interrupts in USB-giveback

In the code path
__usb_hcd_giveback_urb()
-> wdm_in_callback()
-> service_outstanding_interrupt()

The function service_outstanding_interrupt() will unconditionally enable interrupts during unlock and invoke usb_submit_urb() with GFP_KERNEL. If the HCD completes in BH (like ehci does) then the context remains atomic due local_bh_disable() and enabling interrupts does not change this.

Defer the error case handling to a workqueue as suggested by Oliver Neukum. In case of an error the worker performs the read out and wakes the user.

Fixes c1da59dad0eb ("cdc-wdm: Clear read pipeline in case of error")

Cc Robert Foss <[email protected]>

Cc Oliver Neukum <[email protected]>

Signed-off-by Sebastian Andrzej Siewior <[email protected]>