The old implementation was heavy on str* functions and sprintf calls.
This version is more manual, but faster.
Profiling just the printing of a 3 char CAN-id resulted in 60 instructions
for the manual method and over 2000 for the sprintf method. Bear in
mind the profiling was done against libc and not the kernel sprintf.
Together with this rewrite an issue with sending and receiving of RTR frames
has been fixed by Oliver for the cases that the DLC is not zero.
Signed-off-by: Andre Naujoks <nautsch2@gmail.com>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
To be able to use the hex ascii functions in case sensitive environments
the array hex_asc_upper[] and the needed functions for hex_byte_pack_upper()
are introduced.
Signed-off-by: Andre Naujoks <nautsch2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The locking is needed, since the the internal buffer for the CAN frames is
changed during the wakeup call. This could cause buffer inconsistencies
under high loads, especially for the outgoing short CAN packet skbuffs.
The needed locks led to deadlocks before commit
"5ede52538ee2b2202d9dff5b06c33bfde421e6e4 tty: Remove extra wakeup from pty
write() path", which removed the direct callback to the wakeup function from the
tty layer.
As slcan.c is based on slip.c the issue in the original code is fixed, too.
Signed-off-by: Andre Naujoks <nautsch2@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Andre Naujoks