[PATCH 1/3][RESEND] rtlwifi: rtl8192de: Remove redundant variable initializations

[PATCH 1/3][RESEND] rtlwifi: rtl8192de: Remove redundant variable initializations

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The variables rtstatus and place are being initialized with a values
that are never read, the initializations are redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
index 76dd881ef9bb..50c2d8f6f9c0 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
@@ -681,7 +681,7 @@ static bool _rtl92d_phy_bb_config(struct ieee80211_hw *hw)
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_phy *rtlphy = &(rtlpriv->phy);
 	struct rtl_efuse *rtlefuse = rtl_efuse(rtl_priv(hw));
-	bool rtstatus = true;
+	bool rtstatus;
 
 	rtl_dbg(rtlpriv, COMP_INIT, DBG_TRACE, "==>\n");
 	rtstatus = _rtl92d_phy_config_bb_with_headerfile(hw,
@@ -887,7 +887,7 @@ static void _rtl92d_ccxpower_index_check(struct ieee80211_hw *hw,
 
 static u8 _rtl92c_phy_get_rightchnlplace(u8 chnl)
 {
-	u8 place = chnl;
+	u8 place;
 
 	if (chnl > 14) {
 		for (place = 14; place < sizeof(channel5g); place++) {
-- 
2.31.1

[PATCH 2/3][V2] rtlwifi: rtl8192de: make arrays static const, makes object smaller

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Don't populate arrays the stack but instead make them static const. Replace
array channel_info with channel_all since it contains the same data as
channel_all. Makes object code smaller by 961 bytes.

Before:
   text	   data	    bss	    dec	   hex	filename
 128147	  44250	   1024	 173421	 2a56d	../realtek/rtlwifi/rtl8192de/phy.o

After
   text	   data	    bss	    dec	   hex	filename
 127122	  44314	   1024	 172460	 2a1ac	../realtek/rtlwifi/rtl8192de/phy.o

(gcc version 10.2.0)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---

V2: Remove channel_info and replace with channel_all since it is the
    same as channel_info. Thanks to Joe Perches for spotting this.
---
 .../wireless/realtek/rtlwifi/rtl8192de/phy.c  | 48 ++++++++-----------
 1 file changed, 20 insertions(+), 28 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
index 50c2d8f6f9c0..8ae69d914312 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
@@ -160,6 +160,15 @@ static u32 targetchnl_2g[TARGET_CHNL_NUM_2G] = {
 	25711, 25658, 25606, 25554, 25502, 25451, 25328
 };
 
+static const u8 channel_all[59] = {
+	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+	36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58,
+	60, 62, 64, 100, 102, 104, 106, 108, 110, 112,
+	114, 116, 118, 120, 122, 124, 126, 128,	130,
+	132, 134, 136, 138, 140, 149, 151, 153, 155,
+	157, 159, 161, 163, 165
+};
+
 static u32 _rtl92d_phy_calculate_bit_shift(u32 bitmask)
 {
 	u32 i = ffs(bitmask);
@@ -1354,14 +1363,6 @@ static void _rtl92d_phy_switch_rf_setting(struct ieee80211_hw *hw, u8 channel)
 
 u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
 {
-	u8 channel_all[59] = {
-		1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
-		36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58,
-		60, 62, 64, 100, 102, 104, 106, 108, 110, 112,
-		114, 116, 118, 120, 122, 124, 126, 128,	130,
-		132, 134, 136, 138, 140, 149, 151, 153, 155,
-		157, 159, 161, 163, 165
-	};
 	u8 place = chnl;
 
 	if (chnl > 14) {
@@ -3220,37 +3221,28 @@ void rtl92d_phy_config_macphymode_info(struct ieee80211_hw *hw)
 u8 rtl92d_get_chnlgroup_fromarray(u8 chnl)
 {
 	u8 group;
-	u8 channel_info[59] = {
-		1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
-		36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56,
-		58, 60, 62, 64, 100, 102, 104, 106, 108,
-		110, 112, 114, 116, 118, 120, 122, 124,
-		126, 128, 130, 132, 134, 136, 138, 140,
-		149, 151, 153, 155, 157, 159, 161, 163,
-		165
-	};
 
-	if (channel_info[chnl] <= 3)
+	if (channel_all[chnl] <= 3)
 		group = 0;
-	else if (channel_info[chnl] <= 9)
+	else if (channel_all[chnl] <= 9)
 		group = 1;
-	else if (channel_info[chnl] <= 14)
+	else if (channel_all[chnl] <= 14)
 		group = 2;
-	else if (channel_info[chnl] <= 44)
+	else if (channel_all[chnl] <= 44)
 		group = 3;
-	else if (channel_info[chnl] <= 54)
+	else if (channel_all[chnl] <= 54)
 		group = 4;
-	else if (channel_info[chnl] <= 64)
+	else if (channel_all[chnl] <= 64)
 		group = 5;
-	else if (channel_info[chnl] <= 112)
+	else if (channel_all[chnl] <= 112)
 		group = 6;
-	else if (channel_info[chnl] <= 126)
+	else if (channel_all[chnl] <= 126)
 		group = 7;
-	else if (channel_info[chnl] <= 140)
+	else if (channel_all[chnl] <= 140)
 		group = 8;
-	else if (channel_info[chnl] <= 153)
+	else if (channel_all[chnl] <= 153)
 		group = 9;
-	else if (channel_info[chnl] <= 159)
+	else if (channel_all[chnl] <= 159)
 		group = 10;
 	else
 		group = 11;
-- 
2.31.1

Re: [PATCH 2/3][V2] rtlwifi: rtl8192de: make arrays static const, makes object smaller

[Joe Perches]

On Tue, 2021-08-03 at 15:49 +0100, Colin King wrote:
> Don't populate arrays the stack but instead make them static const. Replace
> array channel_info with channel_all since it contains the same data as
> channel_all. Makes object code smaller by 961 bytes.
[]
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
[]
> @@ -160,6 +160,15 @@ static u32 targetchnl_2g[TARGET_CHNL_NUM_2G] = {
>  	25711, 25658, 25606, 25554, 25502, 25451, 25328
>  };
> 
> +static const u8 channel_all[59] = {

I don't believe there is a significant value in sizing the array
as 59 instead of letting the compiler count the elements.

> +	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
> +	36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58,
> +	60, 62, 64, 100, 102, 104, 106, 108, 110, 112,
> +	114, 116, 118, 120, 122, 124, 126, 128,	130,
> +	132, 134, 136, 138, 140, 149, 151, 153, 155,
> +	157, 159, 161, 163, 165
> +};

Re: [PATCH 2/3][V2] rtlwifi: rtl8192de: make arrays static const, makes object smaller

[Colin Ian King]

On 03/08/2021 16:09, Joe Perches wrote:
> On Tue, 2021-08-03 at 15:49 +0100, Colin King wrote:
>> Don't populate arrays the stack but instead make them static const. Replace
>> array channel_info with channel_all since it contains the same data as
>> channel_all. Makes object code smaller by 961 bytes.
> []
>> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> []
>> @@ -160,6 +160,15 @@ static u32 targetchnl_2g[TARGET_CHNL_NUM_2G] = {
>>  	25711, 25658, 25606, 25554, 25502, 25451, 25328
>>  };
>>
>> +static const u8 channel_all[59] = {
> 
> I don't believe there is a significant value in sizing the array
> as 59 instead of letting the compiler count the elements.

I was reluctant to remove this as I supposed the original had it in for
a purpose, e.g. to ensure that the array was not populated with more
data than intended. Does it make much of a difference?

> 
>> +	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
>> +	36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58,
>> +	60, 62, 64, 100, 102, 104, 106, 108, 110, 112,
>> +	114, 116, 118, 120, 122, 124, 126, 128,	130,
>> +	132, 134, 136, 138, 140, 149, 151, 153, 155,
>> +	157, 159, 161, 163, 165
>> +};
> 
> 

Re: [PATCH 2/3][V2] rtlwifi: rtl8192de: make arrays static const, makes object smaller

[Joe Perches]

On Tue, 2021-08-03 at 16:15 +0100, Colin Ian King wrote:
> On 03/08/2021 16:09, Joe Perches wrote:
> > On Tue, 2021-08-03 at 15:49 +0100, Colin King wrote:
> > > Don't populate arrays the stack but instead make them static const. Replace
> > > array channel_info with channel_all since it contains the same data as
> > > channel_all. Makes object code smaller by 961 bytes.
> > []
> > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> > []
> > > @@ -160,6 +160,15 @@ static u32 targetchnl_2g[TARGET_CHNL_NUM_2G] = {
> > >  	25711, 25658, 25606, 25554, 25502, 25451, 25328
> > >  };
> > > 
> > > +static const u8 channel_all[59] = {
> > 
> > I don't believe there is a significant value in sizing the array
> > as 59 instead of letting the compiler count the elements.
> 
> I was reluctant to remove this as I supposed the original had it in for
> a purpose, e.g. to ensure that the array was not populated with more
> data than intended. Does it make much of a difference?
> 
> > 
> > > +	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
> > > +	36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58,
> > > +	60, 62, 64, 100, 102, 104, 106, 108, 110, 112,
> > > +	114, 116, 118, 120, 122, 124, 126, 128,	130,
> > > +	132, 134, 136, 138, 140, 149, 151, 153, 155,
> > > +	157, 159, 161, 163, 165
> > > +};

Dunno.

Maybe not, but I did have to count the elements to see if
it really was 59 or the compiler was adding trailing 0's.

OK I really did a grep to count the commas and added 1...

[PATCH 3/3] rtlwifi: rtl8192de: fix array size limit in for-loop

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Currently the size of the entire array is being used in a for-loop
for the element count. While this works since the elements are u8
sized, it is preferred to use ARRAY_SIZE to get the element count
of the array.

Kudos to Joe Perches for spotting this issue.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
index 8ae69d914312..e11728622a9e 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
@@ -1366,7 +1366,7 @@ u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
 	u8 place = chnl;
 
 	if (chnl > 14) {
-		for (place = 14; place < sizeof(channel_all); place++) {
+		for (place = 14; place < ARRAY_SIZE(channel_all); place++) {
 			if (channel_all[place] == chnl)
 				return place - 13;
 		}
-- 
2.31.1

Re: [PATCH 3/3] rtlwifi: rtl8192de: fix array size limit in for-loop

[Joe Perches]

On Tue, 2021-08-03 at 15:49 +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the size of the entire array is being used in a for-loop
> for the element count. While this works since the elements are u8
> sized, it is preferred to use ARRAY_SIZE to get the element count
> of the array.
[]
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
[]
> @@ -1366,7 +1366,7 @@ u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
>  	u8 place = chnl;
> 
>  	if (chnl > 14) {
> -		for (place = 14; place < sizeof(channel_all); place++) {
> +		for (place = 14; place < ARRAY_SIZE(channel_all); place++) {
>  			if (channel_all[place] == chnl)
>  				return place - 13;
>  		}

Thanks.

It seems a relatively common copy/paste use in rtlwifi

$ git grep -P -n 'for\b.*<\s*sizeof\s*\(\s*\w+\w*\)\s*;' drivers/net/wireless/realtek/rtlwifi/
drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:893:               for (place = 14; place < sizeof(channel5g); place++) {
drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:1368:              for (place = 14; place < sizeof(channel_all); place++) {
drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:2430:      for (i = 0; i < sizeof(channel5g); i++)
drivers/net/wireless/realtek/rtlwifi/rtl8192ee/phy.c:2781:              for (place = 14; place < sizeof(channel_all); place++) {
drivers/net/wireless/realtek/rtlwifi/rtl8723be/phy.c:2170:              for (place = 14; place < sizeof(channel_all); place++) {
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:3610:              for (place = 14; place < sizeof(channel_all); place++)

Re: [PATCH 3/3] rtlwifi: rtl8192de: fix array size limit in for-loop

[Colin Ian King]

On 03/08/2021 19:11, Joe Perches wrote:
> On Tue, 2021-08-03 at 15:49 +0100, Colin King wrote:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> Currently the size of the entire array is being used in a for-loop
>> for the element count. While this works since the elements are u8
>> sized, it is preferred to use ARRAY_SIZE to get the element count
>> of the array.
> []
>> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> []
>> @@ -1366,7 +1366,7 @@ u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
>>  	u8 place = chnl;
>>
>>  	if (chnl > 14) {
>> -		for (place = 14; place < sizeof(channel_all); place++) {
>> +		for (place = 14; place < ARRAY_SIZE(channel_all); place++) {
>>  			if (channel_all[place] == chnl)
>>  				return place - 13;
>>  		}
> 
> Thanks.
> 
> It seems a relatively common copy/paste use in rtlwifi

Urgh. Let's drop patch 3/3 for the moment. I'll send a fix later on, I'm
kinda tied up for the next 24 hours.


> 
> $ git grep -P -n 'for\b.*<\s*sizeof\s*\(\s*\w+\w*\)\s*;' drivers/net/wireless/realtek/rtlwifi/
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:893:               for (place = 14; place < sizeof(channel5g); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:1368:              for (place = 14; place < sizeof(channel_all); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:2430:      for (i = 0; i < sizeof(channel5g); i++)
> drivers/net/wireless/realtek/rtlwifi/rtl8192ee/phy.c:2781:              for (place = 14; place < sizeof(channel_all); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8723be/phy.c:2170:              for (place = 14; place < sizeof(channel_all); place++) {
> drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:3610:              for (place = 14; place < sizeof(channel_all); place++)
> 
> 
> 

Re: [PATCH 3/3] rtlwifi: rtl8192de: fix array size limit in for-loop

[Kalle Valo]

Colin King <colin.king@canonical.com> wrote:

> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the size of the entire array is being used in a for-loop
> for the element count. While this works since the elements are u8
> sized, it is preferred to use ARRAY_SIZE to get the element count
> of the array.
> 
> Kudos to Joe Perches for spotting this issue.
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Dropped per Colin's request.

Patch set to Changes Requested.

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210803144949.79433-3-colin.king@canonical.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH 1/3][RESEND] rtlwifi: rtl8192de: Remove redundant variable initializations

[Kalle Valo]

Colin King <colin.king@canonical.com> wrote:

> From: Colin Ian King <colin.king@canonical.com>
> 
> The variables rtstatus and place are being initialized with a values
> that are never read, the initializations are redundant and can be removed.
> 
> Addresses-Coverity: ("Unused value")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> Acked-by: Ping-Ke Shih <pkshih@realtek.com>

2 patches applied to wireless-drivers-next.git, thanks.

369956ae5720 rtlwifi: rtl8192de: Remove redundant variable initializations
b05897ca8c82 rtlwifi: rtl8192de: make arrays static const, makes object smaller

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210803144949.79433-1-colin.king@canonical.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches