USB: disable reset-resume when USB_QUIRK_RESET is set
The USB_QUIRK_RESET flag indicates that a USB device changes its
identity in some way when it is reset. It may lose its firmware, its
descriptors may change, or it may switch back to a default mode of
operation.
If a device does this, the kernel needs to avoid resetting it. Resets
are likely to fail, or worse, succeed while changing the device's
state in a way the system can't detect.
This means we should disable the reset-resume mechanism whenever this
quirk flag is present. An attempted reset-resume will fail, the
device will be logically disconnected, and later on the hub driver
will rediscover and re-enumerate the device. This will cause the
appropriate udev events to be generated, so that userspace will have a
chance to switch the device into its normal operating mode, if
necessary.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Oliver Neukum <oliver@neukum.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed