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| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2014-03-01 15:31:53 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2014-03-03 14:29:52 +0100 |
| commit | 821047c4055cca833c4674f172a9d73003563eb6 (patch) | |
| tree | 28246c9f50757df9ea1efcad0c8210f098aa1c14 /Documentation | |
| parent | 4b5b82274a17f0ebbf02378df2ba7f36a3f5af19 (diff) | |
| download | linux-821047c4055cca833c4674f172a9d73003563eb6.tar.bz2 | |
can: remove CAN FD compatibility for CAN 2.0 sockets
In commit e2d265d3b587 (canfd: add support for CAN FD in CAN_RAW sockets)
CAN FD frames with a payload length up to 8 byte are passed to legacy
sockets where the CAN FD support was not enabled by the application.
After some discussions with developers at a fair this well meant feature
leads to confusion as no clean switch for CAN / CAN FD is provided to the
application programmer. Additionally a compatibility like this for legacy
CAN_RAW sockets requires some compatibility handling for the sending, e.g.
make CAN2.0 frames a CAN FD frame with BRS at transmission time (?!?).
This will become a mess when people start to develop applications with
real CAN FD hardware. This patch reverts the bad compatibility code
together with the documentation describing the removed feature.
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/can.txt | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index f3089d423515..0cbe6ec22d6f 100644 --- a/Documentation/networking/can.txt +++ b/Documentation/networking/can.txt @@ -554,12 +554,6 @@ solution for a couple of reasons: not specified in the struct can_frame and therefore it is only valid in CANFD_MTU sized CAN FD frames. - As long as the payload length is <=8 the received CAN frames from CAN FD - capable CAN devices can be received and read by legacy sockets too. When - user-generated CAN FD frames have a payload length <=8 these can be send - by legacy CAN network interfaces too. Sending CAN FD frames with payload - length > 8 to a legacy CAN network interface returns an -EMSGSIZE error. - Implementation hint for new CAN applications: To build a CAN FD aware application use struct canfd_frame as basic CAN |