commit bd329e1 ("net: cdc_ncm: do not bind to NCM compatible MBIM devices")
introduced a new policy, preferring MBIM for dual NCM/MBIM functions if
the cdc_mbim driver was enabled. This caused a regression for users
wanting to use NCM.
Devices implementing NCM backwards compatibility according to section
3.2 of the MBIM v1.0 specification allow either NCM or MBIM on a single
USB function, using different altsettings. The cdc_ncm and cdc_mbim
drivers will both probe such functions, and must agree on a common
policy for selecting either MBIM or NCM. Until now, this policy has
been set at build time based on CONFIG_USB_NET_CDC_MBIM.
Use a module parameter to set the system policy at runtime, allowing the
user to prefer NCM on systems with the cdc_mbim driver.
Cc: Greg Suarez <gsuarez@smithmicro.com>
Cc: Alexey Orishko <alexey.orishko@stericsson.com>
Reported-by: Geir Haatveit <nospam@haatveit.nu>
Reported-by: Tommi Kyntola <kynde@ts.ray.fi>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=54791
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
The CDC Mobile Broadband Interface Model (MBIM) specification
extends CDC NCM by
- removing the redundant ethernet header from the point-to-point
USB channel
- adding support for multiple IP (v4 and/or v6) sessions multiplexed
on the same USB channel
- adding a MBIM control channel encapsulated in CDC
- adding Device Service Streams (DSS), which are non IP generic data
streams multiplexed on the same USB channel as the IP sessions
MBIM devices are managed using the dedicated control channel, and no
data will flow on the data channel until a control session has been
established. This driver has no knowledge of MBIM control messages.
It just exports the control channel to a /dev/cdc-wdmX character
device for userspace management applications. Such an application is
therefore required to use this driver.
This patch implements basic MBIM support, reusing the NCM and WDM driver
APIs, currently limited to IP sessions with SessionID 0. DSS and
multiplexed IP sessions are not yet supported.
Signed-off-by: Greg Suarez <gsuarez@smithmicro.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move symbols and definitons which can be shared with a
MBIM driver in a new header.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
