• Arnd Bergmann's avatar
    bna: avoid writing uninitialized data into hw registers · 359f7020
    Arnd Bergmann authored
    
    [ Upstream commit a5af8392 ]
    
    The latest gcc-7 snapshot warns about bfa_ioc_send_enable/bfa_ioc_send_disable
    writing undefined values into the hardware registers:
    
    drivers/net/ethernet/brocade/bna/bfa_ioc.c: In function 'bfa_iocpf_sm_disabling_entry':
    arch/arm/include/asm/io.h:109:22: error: '*((void *)&disable_req+4)' is used uninitialized in this function [-Werror=uninitialized]
    arch/arm/include/asm/io.h:109:22: error: '*((void *)&disable_req+8)' is used uninitialized in this function [-Werror=uninitialized]
    
    The two functions look like they should do the same thing, but only one
    of them initializes the time stamp and clscode field. The fact that we
    only get a warning for one of the two functions seems to be arbitrary,
    based on the inlining decisions in the compiler.
    
    To address this, I'm making both functions do the same thing:
    
    - set the clscode from the ioc structure in both
    - set the time stamp from ktime_get_real_seconds (which also
      avoids the signed-integer overflow in 2038 and extends the
      well-defined behavior until 2106).
    - zero-fill the reserved field
    
    Fixes: 8b230ed8 ("bna: Brocade 10Gb Ethernet device driver")
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    359f7020
bfa_ioc.c 77.6 KB