ethtool: silence warning on bit loss
authorJesse Brandeburg <jesse.brandeburg@intel.com>
Thu, 13 Oct 2016 23:13:55 +0000 (16:13 -0700)
committerDavid S. Miller <davem@davemloft.net>
Fri, 14 Oct 2016 20:05:42 +0000 (16:05 -0400)
Sparse was complaining when we went to prototype some code
using ethtool_cmd_speed_set and SPEED_100000, which uses
the upper 16 bits of __u32 speed for the first time.

CHECK
...
.../uapi/linux/ethtool.h:123:28: warning:
  cast truncates bits from constant value (186a0 becomes 86a0)

The warning is actually bogus, as no bits are really lost, but
we can get rid of the sparse warning with this one small change.

Reported-by: Preethi Banala <preethi.banala@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/uapi/linux/ethtool.h

index 099a4200732cc187f069331cbf3cbfa35e9a7e52..8e547231c1b74bd21ba194127de3b6357cba84b9 100644 (file)
@@ -119,8 +119,7 @@ struct ethtool_cmd {
 static inline void ethtool_cmd_speed_set(struct ethtool_cmd *ep,
                                         __u32 speed)
 {
-
-       ep->speed = (__u16)speed;
+       ep->speed = (__u16)(speed & 0xFFFF);
        ep->speed_hi = (__u16)(speed >> 16);
 }