[PATCH] ath9k: fix channel flag / regd issues with multiple cards

[PATCH] ath9k: fix channel flag / regd issues with multiple cards

[Felix Fietkau]

Since the regulatory code touches the channel array, it needs to be
copied for each device instance. That way the original channel array
can also be made const.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org [all]
---
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -57,7 +57,7 @@ MODULE_PARM_DESC(blink, "Enable LED blin
  * on 5 MHz steps, we support the channels which we know
  * we have calibration data for all cards though to make
  * this static */
-static struct ieee80211_channel ath9k_2ghz_chantable[] = {
+static const struct ieee80211_channel ath9k_2ghz_chantable[] = {
 	CHAN2G(2412, 0), /* Channel 1 */
 	CHAN2G(2417, 1), /* Channel 2 */
 	CHAN2G(2422, 2), /* Channel 3 */
@@ -78,7 +78,7 @@ static struct ieee80211_channel ath9k_2g
  * on 5 MHz steps, we support the channels which we know
  * we have calibration data for all cards though to make
  * this static */
-static struct ieee80211_channel ath9k_5ghz_chantable[] = {
+static const struct ieee80211_channel ath9k_5ghz_chantable[] = {
 	/* _We_ call this UNII 1 */
 	CHAN5G(5180, 14), /* Channel 36 */
 	CHAN5G(5200, 15), /* Channel 40 */
@@ -478,10 +478,17 @@ err:
 	return -EIO;
 }
 
-static void ath9k_init_channels_rates(struct ath_softc *sc)
+static int ath9k_init_channels_rates(struct ath_softc *sc)
 {
+	void *channels;
+
 	if (test_bit(ATH9K_MODE_11G, sc->sc_ah->caps.wireless_modes)) {
-		sc->sbands[IEEE80211_BAND_2GHZ].channels = ath9k_2ghz_chantable;
+		channels = kmemdup(ath9k_2ghz_chantable,
+			sizeof(ath9k_2ghz_chantable), GFP_KERNEL);
+		if (!channels)
+		    return -ENOMEM;
+
+		sc->sbands[IEEE80211_BAND_2GHZ].channels = channels;
 		sc->sbands[IEEE80211_BAND_2GHZ].band = IEEE80211_BAND_2GHZ;
 		sc->sbands[IEEE80211_BAND_2GHZ].n_channels =
 			ARRAY_SIZE(ath9k_2ghz_chantable);
@@ -491,7 +498,15 @@ static void ath9k_init_channels_rates(st
 	}
 
 	if (test_bit(ATH9K_MODE_11A, sc->sc_ah->caps.wireless_modes)) {
-		sc->sbands[IEEE80211_BAND_5GHZ].channels = ath9k_5ghz_chantable;
+		channels = kmemdup(ath9k_5ghz_chantable,
+			sizeof(ath9k_5ghz_chantable), GFP_KERNEL);
+		if (!channels) {
+			if (sc->sbands[IEEE80211_BAND_2GHZ].channels)
+				kfree(sc->sbands[IEEE80211_BAND_2GHZ].channels);
+			return -ENOMEM;
+		}
+
+		sc->sbands[IEEE80211_BAND_5GHZ].channels = channels;
 		sc->sbands[IEEE80211_BAND_5GHZ].band = IEEE80211_BAND_5GHZ;
 		sc->sbands[IEEE80211_BAND_5GHZ].n_channels =
 			ARRAY_SIZE(ath9k_5ghz_chantable);
@@ -500,6 +515,7 @@ static void ath9k_init_channels_rates(st
 		sc->sbands[IEEE80211_BAND_5GHZ].n_bitrates =
 			ARRAY_SIZE(ath9k_legacy_rates) - 4;
 	}
+	return 0;
 }
 
 static void ath9k_init_misc(struct ath_softc *sc)
@@ -602,8 +618,11 @@ static int ath9k_init_softc(u16 devid, s
 	if (ret)
 		goto err_btcoex;
 
+	ret = ath9k_init_channels_rates(sc);
+	if (ret)
+		goto err_btcoex;
+
 	ath9k_init_crypto(sc);
-	ath9k_init_channels_rates(sc);
 	ath9k_init_misc(sc);
 
 	return 0;
@@ -784,6 +803,12 @@ static void ath9k_deinit_softc(struct at
 {
 	int i = 0;
 
+	if (sc->sbands[IEEE80211_BAND_2GHZ].channels)
+		kfree(sc->sbands[IEEE80211_BAND_2GHZ].channels);
+
+	if (sc->sbands[IEEE80211_BAND_5GHZ].channels)
+		kfree(sc->sbands[IEEE80211_BAND_5GHZ].channels);
+
         if ((sc->btcoex.no_stomp_timer) &&
 	    sc->sc_ah->btcoex_hw.scheme == ATH_BTCOEX_CFG_3WIRE)
 		ath_gen_timer_free(sc->sc_ah, sc->btcoex.no_stomp_timer);

Re: [PATCH] ath9k: fix channel flag / regd issues with multiple cards

[Felix Fietkau]

On 2010-10-01 1:06 AM, Felix Fietkau wrote:
> Since the regulatory code touches the channel array, it needs to be
> copied for each device instance. That way the original channel array
> can also be made const.
> 
> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
> Cc: stable@kernel.org [all]
Hmm, don't merge this one just yet. Seems that this may not be the cause
for the weird multi-card regd issues after all, since the code looks
like that part should be properly locked, even for multiple wiphys
sharing the same channel list.

- Felix

Re: [PATCH] ath9k: fix channel flag / regd issues with multiple cards

[Felix Fietkau]

On 2010-10-01 1:37 AM, Felix Fietkau wrote:
> On 2010-10-01 1:06 AM, Felix Fietkau wrote:
>> Since the regulatory code touches the channel array, it needs to be
>> copied for each device instance. That way the original channel array
>> can also be made const.
>> 
>> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
>> Cc: stable@kernel.org [all]
> Hmm, don't merge this one just yet. Seems that this may not be the cause
> for the weird multi-card regd issues after all, since the code looks
> like that part should be properly locked, even for multiple wiphys
> sharing the same channel list.
I got user confirmation that this patch does indeed help with this
issue. I think we should merge this patch until we figure out why
sharing the channel list over multiple devices causes these issues.
Without this patch, the channel flags can get messed up in a way that
breaks regulatory compliance.

- Felix