The io_syscallX wrappers in syscall-mips.h discard error return status
by overwriting the value returned in v0 from the system call with -1.
Modify this behavior by returning the negative of the return value on
error (as identified by a3 != 0). This convention is consistent with
the behavior observed in syscall-ppc.h.
For a description of the MIPS system call interface, see:
http://www.linux-mips.org/wiki/Syscall
Signed-off-by: Phil Staub <Phil.Staub@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
