This patch tries to optimize the calculation of the sample point. To
understand what it does have a look at the original implementation.
If there is a combination of timing parameters where both the bitrate
and sample point error are 0 the current implementation will find it.
However if the reference clock doesn't allow an optimal bitrate (this
means the bitrate error is always != 0) there might be several timing
parameter combinations having the same bitrate error. The original
implementation will allways choose the one with the highest brp. The
actual sample point error isn't taken into account.
This patch changes the algorithm to minimize the sample point error,
too. Now a brp/tseg combination is accepted as better if one of these
condition are fulfilled:
1) the bit rate error must be smaller, or
2) the bit rate error must be equal and
the sample point error must be equal or smaller
If a smaller bit rate error is found the sample point error is reset.
This ensures that we first optimize for small bit rate error and then
for small sample point errors.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* rtnetlink:
Revert "j1939.page: add relevant API calls"
testj1939: print API calls
j1939.page: add relevant API calls
j1939.page: restructure
testj1939: use send() when connect()ed
testj1939: remember if peername was provided
add .gitignore
import sample program & help page
initial
Upstream commit ba61a8d9d780980e8284355a0be750897e7af212
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit?id=ba61a8d9d780980e8284355a0be750897e7af212
The can subsystem communicates with user space using a bcm_msg_head
header, which contains two timestamps. This is problematic for
multiple reasons:
a) The structure layout is currently incompatible between 64-bit
user space and 32-bit user space, and cannot work in compat
mode (other than x32).
b) The timeval structure layout will change in 32-bit user
space when we fix the y2038 overflow problem by redefining
time_t to 64-bit, making new 32-bit user space incompatible
with the current kernel interface.
Cars last a long time and often use old kernels, so the actual
users of this code are the most likely ones to migrate to y2038
safe user space.
This tries to work around part of the problem by changing the
publicly visible user interface in the header, but not the binary
interface. Fortunately, the values passed around in the structure
are relative times and do not actually suffer from the y2038
overflow, so 32-bit is enough here.
We replace the use of 'struct timeval' with a newly defined
'struct bcm_timeval' that uses the exact same binary layout
as before and that still suffers from problem a) but not problem
b).
The downside of this approach is that any user space program
that currently assigns a timeval structure to these members
rather than writing the tv_sec/tv_usec portions individually
will suffer a compile-time error when built with an updated
kernel header. Fixing this error makes it work fine with old
and new headers though.
We could address problem a) by using '__u32' or 'int' members
rather than 'long', but that would have a more significant
downside in also breaking support for all existing 64-bit user
binaries that might be using this interface, which is likely
not acceptable.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-can@vger.kernel.org
Cc: linux-api@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Maximilian Pachl <m@ximilian.info>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sven Schmitt <sven.schmitt@gmx.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sven Schmitt <sven.schmitt@gmx.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Including <sys/ioctl.h> and <net/if.h> is not sufficient
to musl to find SIOCSIFNAME, so <linux/sockios.h> must be
included too.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Without this patch compilation against musl C library
breaks, because struct timeval cannot be found.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
replaced strcpy(if_name, argv[x]) + ioctl by if_idx = if_nametoindex(argv[x])
to avoid overflows caused by long user input.
Signed-off-by: Sven Schmitt <sven.schmitt@gmx.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Similar to referencing iptables rules by their line number this UID allows to
reference created routing jobs, e.g. to alter configured data modifications.
The UID is an optional non-zero value which can be provided at routing job
creation time. When the UID is set the UID replaces the data modification
configuration as job identification attribute e.g. at job removal time.
The UID option is provided by mainline Linux 4.2+
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
add v command response. Some software like USBtinViewer using v for software version.
Tested on USBtinViewer 1.0
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The result of (last_log_tv.tv_sec - log_tv.tv_sec) is
unsigned long, so use labs() in order not to trim the
value to int. Make skipgap to unsigned long for the same
reason.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
The CAN_RAW socket can set multiple CAN identifier specific filters that lead
to multiple filters in the af_can.c filter processing. These filters are
indenpendent from each other which leads to logical OR'ed filters when applied.
This socket option joines the given CAN filters in the way that only CAN frames
are passed to user space that matched *all* given CAN filters. The semantic for
the applied filters is therefore changed to a logical AND.
This is useful especially when the filterset is a combination of filters where
the CAN_INV_FILTER flag is set in order to notch single CAN IDs or CAN ID
ranges from the incoming traffic.
Example:
candump can0,100~7FF,200~7FF,400~7FF (logical OR'ed filters)
candump can0,100~7FF,200~7FF,400~7FF,J (logical AND'ed filters)
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
outfile is closed as well, so do this symmetrically for infile.
Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Marc Kleine-Budde
Ramesh Shanmugasundaram
Kurt Van Dijck
Kurt Van Dijck
Kurt Van Dijck
Oliver Hartkopp
Maximilian Pachl
Sven Schmitt
Andrew Berezovskyi
Yegor Yefremov
bombilee
Robert Schwebel