[PATCH] wireless: Fix WARN_ON() with ieee802.11b

[PATCH] wireless: Fix WARN_ON() with ieee802.11b

[Ivo van Doorn]

When the driver registers a IEEE80211_BAND_2GHZ band,
it can either be 802.11b or 802.11g. But when 802.11b rates
are registered "want" will be 3 (since 4 rates are being registered,
and each of those 4 rates will decrease "want").
Since this is a correct situation, there is no need to trigger
a WARN_ON() for this.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>

---
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 0dcccbf..5304c62 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -80,7 +80,7 @@ static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
 				sband->bitrates[i].flags |=
 					IEEE80211_RATE_ERP_G;
 		}
-		WARN_ON(want != 0 && want != 6);
+		WARN_ON(want != 0 && want != 3 && want != 6);
 		break;
 	case IEEE80211_NUM_BANDS:
 		WARN_ON(1);

Re: [PATCH] wireless: Fix WARN_ON() with ieee802.11b

[Nick Kossifidis]

2008/2/3, Ivo van Doorn <ivdoorn@gmail.com>:
> When the driver registers a IEEE80211_BAND_2GHZ band,
> it can either be 802.11b or 802.11g. But when 802.11b rates
> are registered "want" will be 3 (since 4 rates are being registered,
> and each of those 4 rates will decrease "want").
> Since this is a correct situation, there is no need to trigger
> a WARN_ON() for this.
>
> Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
>
> ---
> diff --git a/net/wireless/util.c b/net/wireless/util.c
> index 0dcccbf..5304c62 100644
> --- a/net/wireless/util.c
> +++ b/net/wireless/util.c
> @@ -80,7 +80,7 @@ static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
>                                 sband->bitrates[i].flags |=
>                                         IEEE80211_RATE_ERP_G;
>                 }
> -               WARN_ON(want != 0 && want != 6);
> +               WARN_ON(want != 0 && want != 3 && want != 6);
>                 break;
>         case IEEE80211_NUM_BANDS:
>                 WARN_ON(1);

Had the same problem when registering an AR5211 card (a/b only), this
patch fixes it ;-)

Acked-by: Nick Kossifidis <mickflemm@gmail.com>

-- 
GPG ID: 0xD21DB2DB
As you read this post global entropy rises. Have Fun ;-)
Nick

Re: [PATCH] wireless: Fix WARN_ON() with ieee802.11b

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 512 bytes --]


> When the driver registers a IEEE80211_BAND_2GHZ band,
> it can either be 802.11b or 802.11g. But when 802.11b rates
> are registered "want" will be 3 (since 4 rates are being registered,
> and each of those 4 rates will decrease "want").

Huh, yeah, you're right, this is a thinko.

> -		WARN_ON(want != 0 && want != 6);
> +		WARN_ON(want != 0 && want != 3 && want != 6);

However, I think it should just be

		WARN_ON(want != 0 && want != 3);

6 just doesn't make sense, does it?

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]

Re: [PATCH] wireless: Fix WARN_ON() with ieee802.11b

[Ivo van Doorn]

On Sunday 03 February 2008, Johannes Berg wrote:
> 
> > When the driver registers a IEEE80211_BAND_2GHZ band,
> > it can either be 802.11b or 802.11g. But when 802.11b rates
> > are registered "want" will be 3 (since 4 rates are being registered,
> > and each of those 4 rates will decrease "want").
> 
> Huh, yeah, you're right, this is a thinko.
> 
> > -		WARN_ON(want != 0 && want != 6);
> > +		WARN_ON(want != 0 && want != 3 && want != 6);
> 
> However, I think it should just be
> 
> 		WARN_ON(want != 0 && want != 3);
> 
> 6 just doesn't make sense, does it?

Well from your code it seemed that you only made 1Mbit mandatory for
802.11b. So if you want to make all b rates mandatory then the 6 check should
indeed be removed.
But shouldn't the 2Mbit, 5.5Mbit and 11Mbit set as IEEE80211_RATE_MANDATORY_B
as well?

Ivo

Re: [PATCH] wireless: Fix WARN_ON() with ieee802.11b

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 404 bytes --]


> Well from your code it seemed that you only made 1Mbit mandatory for
> 802.11b. So if you want to make all b rates mandatory then the 6 check should
> indeed be removed.
> But shouldn't the 2Mbit, 5.5Mbit and 11Mbit set as IEEE80211_RATE_MANDATORY_B
> as well?

Ah, right, no, those aren't mandatory afaict so your patch is correct.
This is only a fairly lax sanity check anyway.

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]

Re: [PATCH] wireless: Fix WARN_ON() with ieee802.11b

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 993 bytes --]


On Sat, 2008-02-02 at 23:53 +0100, Ivo van Doorn wrote:
> When the driver registers a IEEE80211_BAND_2GHZ band,
> it can either be 802.11b or 802.11g. But when 802.11b rates
> are registered "want" will be 3 (since 4 rates are being registered,
> and each of those 4 rates will decrease "want").
> Since this is a correct situation, there is no need to trigger
> a WARN_ON() for this.
> 
> Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>

Acked-by: Johannes Berg <johannes@sipsolutions.net>

> ---
> diff --git a/net/wireless/util.c b/net/wireless/util.c
> index 0dcccbf..5304c62 100644
> --- a/net/wireless/util.c
> +++ b/net/wireless/util.c
> @@ -80,7 +80,7 @@ static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
>  				sband->bitrates[i].flags |=
>  					IEEE80211_RATE_ERP_G;
>  		}
> -		WARN_ON(want != 0 && want != 6);
> +		WARN_ON(want != 0 && want != 3 && want != 6);
>  		break;
>  	case IEEE80211_NUM_BANDS:
>  		WARN_ON(1);
> 

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]