Message ID | 5175F7F7.7000703@asianux.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
I will send patch v3 for properly capitalizing my comments' sentences and subject. On 2013年04月23日 10:54, Chen Gang wrote: > > need change ~(u8)0 to 0xff, or in mac802154_wpan_xmit(), "u8 chan" > will never == MAC802154_CHAN_NONE. > > the related warning: > net/mac802154/wpan.c:325:2: warning: comparison is always false > due to limited range of data type [-Wtype-limits] > > related unit test: > cc -Wall -O2 -o test test.c > ./test > will output 'different' > > (after use '0xff' instead of '~(u8)0', it will output 'equal') > > -----------------------test code begin-------------------------------- > > #include <stdio.h> > > typedef unsigned char u8; > > int main() > { > u8 uc = 0xff; > > if (uc == ~(u8)0) > printf("\nequal\n"); > else > printf("\ndifferent\n"); > > return 0; > } > > -----------------------test code end---------------------------------- > > > Signed-off-by: Chen Gang <gang.chen@asianux.com> > --- > net/mac802154/mac802154.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/net/mac802154/mac802154.h b/net/mac802154/mac802154.h > index 5c9e021..d48422e 100644 > --- a/net/mac802154/mac802154.h > +++ b/net/mac802154/mac802154.h > @@ -88,7 +88,7 @@ struct mac802154_sub_if_data { > > #define mac802154_to_priv(_hw) container_of(_hw, struct mac802154_priv, hw) > > -#define MAC802154_CHAN_NONE (~(u8)0) /* No channel is assigned */ > +#define MAC802154_CHAN_NONE 0xff /* No channel is assigned */ > > extern struct ieee802154_reduced_mlme_ops mac802154_mlme_reduced; > extern struct ieee802154_mlme_ops mac802154_mlme_wpan; >
diff --git a/net/mac802154/mac802154.h b/net/mac802154/mac802154.h index 5c9e021..d48422e 100644 --- a/net/mac802154/mac802154.h +++ b/net/mac802154/mac802154.h @@ -88,7 +88,7 @@ struct mac802154_sub_if_data { #define mac802154_to_priv(_hw) container_of(_hw, struct mac802154_priv, hw) -#define MAC802154_CHAN_NONE (~(u8)0) /* No channel is assigned */ +#define MAC802154_CHAN_NONE 0xff /* No channel is assigned */ extern struct ieee802154_reduced_mlme_ops mac802154_mlme_reduced; extern struct ieee802154_mlme_ops mac802154_mlme_wpan;
need change ~(u8)0 to 0xff, or in mac802154_wpan_xmit(), "u8 chan" will never == MAC802154_CHAN_NONE. the related warning: net/mac802154/wpan.c:325:2: warning: comparison is always false due to limited range of data type [-Wtype-limits] related unit test: cc -Wall -O2 -o test test.c ./test will output 'different' (after use '0xff' instead of '~(u8)0', it will output 'equal') -----------------------test code begin-------------------------------- #include <stdio.h> typedef unsigned char u8; int main() { u8 uc = 0xff; if (uc == ~(u8)0) printf("\nequal\n"); else printf("\ndifferent\n"); return 0; } -----------------------test code end---------------------------------- Signed-off-by: Chen Gang <gang.chen@asianux.com> --- net/mac802154/mac802154.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)