| Message ID | 20180207202634.98937-1-mka@chromium.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
On 02/07/2018 02:26 PM, Matthias Kaehlcke wrote: > In _rtl92c_get_txpower_writeval_by_regulatory() the variable writeVal > is assigned to itself in an if ... else statement, apparently only to > document that the branch condition is handled and that a previously read > value should be returned unmodified. The self-assignment causes clang to > raise the following warning: > > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c:304:13: > error: explicitly assigning value of variable of type 'u32' > (aka 'unsigned int') to itself [-Werror,-Wself-assign] > writeVal = writeVal; > > Replace the self-assignment with a semicolon, which still serves to > document the 'handling' of the branch condition. > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org> > --- > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > index 9cff6bc4049c..4db92496c122 100644 > --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > @@ -301,7 +301,7 @@ static void _rtl92c_get_txpower_writeval_by_regulatory(struct ieee80211_hw *hw, > writeVal = writeVal - 0x06060606; > else if (rtlpriv->dm.dynamic_txhighpower_lvl == > TXHIGHPWRLEVEL_BT2) > - writeVal = writeVal; > + ; > *(p_outwriteval + rf) = writeVal; > } > } > As the branch condition does nothing, why not remove it and save the compiler's optimizer a bit of work? The code looks strange, but it matches the rest of Realtek's USB drivers. Larry
El Wed, Feb 07, 2018 at 02:35:59PM -0600 Larry Finger ha dit: > On 02/07/2018 02:26 PM, Matthias Kaehlcke wrote: > > In _rtl92c_get_txpower_writeval_by_regulatory() the variable writeVal > > is assigned to itself in an if ... else statement, apparently only to > > document that the branch condition is handled and that a previously read > > value should be returned unmodified. The self-assignment causes clang to > > raise the following warning: > > > > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c:304:13: > > error: explicitly assigning value of variable of type 'u32' > > (aka 'unsigned int') to itself [-Werror,-Wself-assign] > > writeVal = writeVal; > > > > Replace the self-assignment with a semicolon, which still serves to > > document the 'handling' of the branch condition. > > > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org> > > --- > > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > > index 9cff6bc4049c..4db92496c122 100644 > > --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > > +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > > @@ -301,7 +301,7 @@ static void _rtl92c_get_txpower_writeval_by_regulatory(struct ieee80211_hw *hw, > > writeVal = writeVal - 0x06060606; > > else if (rtlpriv->dm.dynamic_txhighpower_lvl == > > TXHIGHPWRLEVEL_BT2) > > - writeVal = writeVal; > > + ; > > *(p_outwriteval + rf) = writeVal; > > } > > } > > > > As the branch condition does nothing, why not remove it and save the > compiler's optimizer a bit of work? The code looks strange, but it matches > the rest of Realtek's USB drivers. Sure, I am happy to change it to whatever the authors/maintainers prefer. I'll wait a bit before respinning for if others feel strongly about keeping the branch.
On Wed, 2018-02-07 at 12:51 -0800, Matthias Kaehlcke wrote: > El Wed, Feb 07, 2018 at 02:35:59PM -0600 Larry Finger ha dit: > > > On 02/07/2018 02:26 PM, Matthias Kaehlcke wrote: > > > In _rtl92c_get_txpower_writeval_by_regulatory() the variable writeVal > > > is assigned to itself in an if ... else statement, apparently only to > > > document that the branch condition is handled and that a previously read > > > value should be returned unmodified. The self-assignment causes clang to > > > raise the following warning: > > > > > > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c:304:13: > > > error: explicitly assigning value of variable of type 'u32' > > > (aka 'unsigned int') to itself [-Werror,-Wself-assign] > > > writeVal = writeVal; > > > > > > Replace the self-assignment with a semicolon, which still serves to > > > document the 'handling' of the branch condition. > > > > > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org> > > > --- > > > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > > > index 9cff6bc4049c..4db92496c122 100644 > > > --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > > > +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c > > > @@ -301,7 +301,7 @@ static void _rtl92c_get_txpower_writeval_by_regulatory(struct ieee80211_hw > *hw, > > > writeVal = writeVal - 0x06060606; > > > else if (rtlpriv->dm.dynamic_txhighpower_lvl == > > > TXHIGHPWRLEVEL_BT2) > > > - writeVal = writeVal; > > > + ; > > > *(p_outwriteval + rf) = writeVal; > > > } > > > } > > > > > > > As the branch condition does nothing, why not remove it and save the > > compiler's optimizer a bit of work? The code looks strange, but it matches > > the rest of Realtek's USB drivers. Agree Larry's comment. > > Sure, I am happy to change it to whatever the authors/maintainers prefer. > > I'll wait a bit before respinning for if others feel strongly about > keeping the branch. > > ------Please consider the environment before printing this e-mail.
diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c index 9cff6bc4049c..4db92496c122 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c @@ -301,7 +301,7 @@ static void _rtl92c_get_txpower_writeval_by_regulatory(struct ieee80211_hw *hw, writeVal = writeVal - 0x06060606; else if (rtlpriv->dm.dynamic_txhighpower_lvl == TXHIGHPWRLEVEL_BT2) - writeVal = writeVal; + ; *(p_outwriteval + rf) = writeVal; } }
In _rtl92c_get_txpower_writeval_by_regulatory() the variable writeVal is assigned to itself in an if ... else statement, apparently only to document that the branch condition is handled and that a previously read value should be returned unmodified. The self-assignment causes clang to raise the following warning: drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c:304:13: error: explicitly assigning value of variable of type 'u32' (aka 'unsigned int') to itself [-Werror,-Wself-assign] writeVal = writeVal; Replace the self-assignment with a semicolon, which still serves to document the 'handling' of the branch condition. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> --- drivers/net/wireless/realtek/rtlwifi/rtl8192cu/rf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)