Re: [PATCH] rtlwifi: rtl8192cu: Remove variable self-assignment in rf.c

[Pkshih]

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 
> > > ---
> > >   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.

Re: [PATCH] rtlwifi: rtl8192cu: Remove variable self-assignment in rf.c

[Matthias Kaehlcke]

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 
> > ---
> >   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.

Re: [PATCH] rtlwifi: rtl8192cu: Remove variable self-assignment in rf.c

[Larry Finger]

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 
---
  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

[PATCH] rtlwifi: rtl8192cu: Remove variable self-assignment in rf.c

[Matthias Kaehlcke]

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 
---
 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;
}
 }
-- 
2.16.0.rc1.238.g530d649a79-goog