Classification of BSS with different frequencies in KHz

Classification of BSS with different frequencies in KHz

[JUN-KYU SHIN]

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"freq_offset" also needs to be compared on S1G Band.
If freq_offset comparison is omitted in cmp_bss, other bss cannot be distinguished in units of khz.

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From 39e6b6b9ecf0b301223dd9e34715e9d103573ff7 Mon Sep 17 00:00:00 2001
From: JUN-KYU SHIN <jk.shin@newratek.com>
Date: Wed, 9 Nov 2022 14:35:49 +0900
Subject: [PATCH] Classification of BSS with different frequencies in KHz.

"freq_offset" also needs to be compared on S1G Band.
If freq_offset comparison is omitted in cmp_bss,
other bss cannot be distinguished in units of khz.

Signed-off-by: JUN-KYU SHIN <jk.shin@newratek.com>
---
 net/wireless/scan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 806a5f1330ff..3cfc668c4189 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1289,7 +1289,8 @@ static int cmp_bss(struct cfg80211_bss *a,
 	int i, r;
 
 	if (a->channel != b->channel)
-		return b->channel->center_freq - a->channel->center_freq;
+		return ((b->channel->center_freq + b->channel->freq_offset) -
+					(a->channel->center_freq + a->channel->freq_offset));
 
 	a_ies = rcu_access_pointer(a->ies);
 	if (!a_ies)
-- 
2.25.1

Re: Classification of BSS with different frequencies in KHz

[Johannes Berg]

On Wed, 2022-11-09 at 15:15 +0900, JUN-KYU SHIN wrote:
> "freq_offset" also needs to be compared on S1G Band.
> If freq_offset comparison is omitted in cmp_bss, other bss cannot be distinguished in units of khz.


please don't send patches as attachments.

The patch looks wrong, the freq offset is in different units, so this
could cause bad == comparisons?

johannes

Re: [PATCH] Classification of BSS with different frequencies in KHz.

[JUN-KYU SHIN]

Hi johannes,

First of all, thank you very much for the review and feedback.
This mail is corrected part of your feedback.


Signed-off-by: JUN-KYU SHIN <jk.shin@newratek.com>
---
 net/wireless/scan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 3cfc668c4189..22ae8996ada3 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1289,8 +1289,8 @@ static int cmp_bss(struct cfg80211_bss *a,
 	int i, r;
 
 	if (a->channel != b->channel)
-		return ((b->channel->center_freq + b->channel->freq_offset) -
-					(a->channel->center_freq + a->channel->freq_offset));
+		return ((b->channel->center_freq + (u32)b->channel->freq_offset) -
+					(a->channel->center_freq + (u32)a->channel->freq_offset));
 
 	a_ies = rcu_access_pointer(a->ies);
 	if (!a_ies)
-- 
2.25.1

[PATCH v2] wifi: cfg80211: Classification of BSS with different frequencies in the S1G Band.

[JUN-KYU SHIN]

If the "channel->freq_offset" comparison is omitted in cmp_bss(),
BSS with different kHz units cannot be distinguished in the S1G Band.
So "freq_offset" should also be included in the comparison.

Signed-off-by: JUN-KYU SHIN <jk.shin@newratek.com>
---
 net/wireless/scan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 22ae8996ada3..6bba130ea670 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1289,8 +1289,8 @@ static int cmp_bss(struct cfg80211_bss *a,
 	int i, r;
 
 	if (a->channel != b->channel)
-		return ((b->channel->center_freq + (u32)b->channel->freq_offset) -
-					(a->channel->center_freq + (u32)a->channel->freq_offset));
+		return ((b->channel->center_freq * 1000 + b->channel->freq_offset) -
+					(a->channel->center_freq * 1000 + a->channel->freq_offset));
 
 	a_ies = rcu_access_pointer(a->ies);
 	if (!a_ies)
-- 
2.25.1

Re: [PATCH v2] wifi: cfg80211: Classification of BSS with different frequencies in the S1G Band.

[Johannes Berg]

On Thu, 2022-11-10 at 14:48 +0900, JUN-KYU SHIN wrote:
> If the "channel->freq_offset" comparison is omitted in cmp_bss(),
> BSS with different kHz units cannot be distinguished in the S1G Band.
> So "freq_offset" should also be included in the comparison.
> 
> Signed-off-by: JUN-KYU SHIN <jk.shin@newratek.com>
> ---
>  net/wireless/scan.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/wireless/scan.c b/net/wireless/scan.c
> index 22ae8996ada3..6bba130ea670 100644
> --- a/net/wireless/scan.c
> +++ b/net/wireless/scan.c
> @@ -1289,8 +1289,8 @@ static int cmp_bss(struct cfg80211_bss *a,
>  	int i, r;
>  
>  	if (a->channel != b->channel)
> -		return ((b->channel->center_freq + (u32)b->channel->freq_offset) -
> -					(a->channel->center_freq + (u32)a->channel->freq_offset));
> +		return ((b->channel->center_freq * 1000 + b->channel->freq_offset) -
> +					(a->channel->center_freq * 1000 + a->channel->freq_offset));
> 

Looks like that patch would apply on top of your other patch, you need
to resend a complete new patch instead please.

johannes

[PATCH v3] wifi: cfg80211: Classification of BSS with different frequencies in the S1G Band.

[JUN-KYU SHIN]

If the "channel->freq_offset" comparison is omitted in cmp_bss(),
BSS with different kHz units cannot be distinguished in the S1G Band.
So "freq_offset" should also be included in the comparison.

Signed-off-by: JUN-KYU SHIN <jk.shin@newratek.com>
---
 net/wireless/scan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 806a5f1330ff..6bba130ea670 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1289,7 +1289,8 @@ static int cmp_bss(struct cfg80211_bss *a,
 	int i, r;
 
 	if (a->channel != b->channel)
-		return b->channel->center_freq - a->channel->center_freq;
+		return ((b->channel->center_freq * 1000 + b->channel->freq_offset) -
+					(a->channel->center_freq * 1000 + a->channel->freq_offset));
 
 	a_ies = rcu_access_pointer(a->ies);
 	if (!a_ies)
-- 
2.25.1

Re: [PATCH v3] wifi: cfg80211: Classification of BSS with different frequencies in the S1G Band.

[Johannes Berg]

On Thu, 2022-11-10 at 17:18 +0900, JUN-KYU SHIN wrote:
> If the "channel->freq_offset" comparison is omitted in cmp_bss(),
> BSS with different kHz units cannot be distinguished in the S1G Band.
> So "freq_offset" should also be included in the comparison.
> 
> Signed-off-by: JUN-KYU SHIN <jk.shin@newratek.com>
> ---
>  net/wireless/scan.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/wireless/scan.c b/net/wireless/scan.c
> index 806a5f1330ff..6bba130ea670 100644
> --- a/net/wireless/scan.c
> +++ b/net/wireless/scan.c
> @@ -1289,7 +1289,8 @@ static int cmp_bss(struct cfg80211_bss *a,
>  	int i, r;
>  
>  	if (a->channel != b->channel)
> -		return b->channel->center_freq - a->channel->center_freq;
> +		return ((b->channel->center_freq * 1000 + b->channel->freq_offset) -
> +					(a->channel->center_freq * 1000 + a->channel->freq_offset));
> 

And while we're at it - you don't need the outer parentheses on a return
statement, and the indentation could be lining up properly so that a->
is under b->

johannes