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path: root/drivers/net/usb/cdc_mbim.c
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* net: cdc_mbim: send ZLP only for the specific buggy deviceBjørn Mork2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reverting 328d7b8 and instead adding an exception for the Sierra Wireless MC7710. commit 328d7b8 (net: cdc_mbim: send ZLP after max sized NTBs) added a workaround for an issue observed on one specific device. Concerns were raised that this workaround adds a performance penalty to all devices based on questionable, if not buggy, behaviour of a single device: "If you add ZLP for NTBs of dwNtbOutMaxSize, you are heavily affecting CPU load, increasing interrupt load by factor of 2 in high load traffic scenario and possibly decreasing throughput for all other devices which behaves correctly." "The idea of NCM was to avoid extra ZLPs. If your transfer is exactly dwNtbOutMaxSize, it's known, you can submit such request on the receiver side and you do not need any EOT indicatation, so the frametime can be used for useful data." Adding a device specific exception to prevent the workaround from affecting well behaved devices. The assumption here is that needing a ZLP is truly an *exception*. We do not yet have enough data to verify this. The generic workaround in commit 328d7b8 should be considered acceptable despite the performance penalty if the exception list becomes a maintainance hassle. Cc: Alexey ORISHKO <alexey.orishko@stericsson.com> Cc: Yauheni Kaliuta <y.kaliuta@gmail.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: cdc_mbim: send ZLP after max sized NTBsBjørn Mork2013-01-21
| | | | | | | | | | | | | | | We normally avoid sending ZLPs by padding NTBs with a zero byte if the NTB is shorter than dwNtbOutMaxSize, resulting in a short USB packet instead of a ZLP. But in the case where the NTB length is exactly dwNtbOutMaxSize and this is an exact multiplum of wMaxPacketSize, then we must send a ZLP. This fixes an issue seen on a Sierra Wireless MC7710 device where the transmission would fail whenever we ended up padding the NTBs to max size. Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: cdc_mbim: Device Service Stream supportBjørn Mork2012-10-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MBIM devices can support up to 256 generic streams called Device Service Streams (DSS). The MBIM spec says The format of the Device Service Stream payload depends on the device service (as identified by the corresponding UUID) that is used when opening the data stream. Example use cases are serial AT command interfaces and NMEA data streams. We cannot make any assumptions about these device services. Adding support for Device Service Stream by extending the MBIM session to VLAN mapping scheme, allocating VLAN IDs 256 to 511 for DSS, using the DSS SessionID as the lower 8bit of the VLAN ID. Using a netdev for DSS keeps the device framing intact and allows userspace to do whatever it want with the streams. For example, exporting an AT command interface using DSS session #0 to a PTY for use with a terminal application like minicom: vconfig add wwan0 256 ip link set dev wwan0 up ip link set dev wwan0.256 up socat INTERFACE:wwan0.256,type=2 PTY:,echo=0,link=/tmp/modem Device configuration must be done using MBIM control commands over the /dev/cdc-wdmx device. The userspace management application should coordinate host VLAN configuration and the device MBIM configuration using the device capabilities to find out if it needs to set up PTY mappings etc. Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: cdc_ncm: map MBIM IPS SessionID to VLAN IDBjørn Mork2012-10-23
| | | | | | | | | | | MBIM devices can support up to 256 independent IP Streams. The main network device will only handle SessionID 0. Mapping SessionIDs 1 to 255 to VLANs using the SessionID as VLAN ID allow userspace to use these streams with traditional tools like vconfig. Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: cdc_mbim: adding MBIM driverGreg Suarez2012-10-23
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>