[ath9k-devel] Hardware or software limitation?

[ath9k-devel] Hardware or software limitation?

[Seth Baker]

I have two adaptors with AR9280 chipsets. I can use 5Ghz AP mode on one, but not the other. 
I thought it was a regdom problem but I have used custom static db.txt files in recompiled crda and recompiled 80211 modules until I've gone crosseyed. This never changes the capabilities of the 5ghz channels as listed below.? Look at the partial output of iw list of the 2 adaptors. The exact same system was used. Is this a limitation of? the hardware or is it something else?

NetGear, Inc. WNDA3200 802.11abgn Wireless Adapter [Atheros AR7010+AR9280:
??????????? ??? Band 2:
??? ??? Capabilities: 0x114e
??? ??? ??? HT20/HT40
??? ??? ??? SM Power Save disabled
??? ??? ??? RX HT40 SGI
??? ??? ??? RX STBC 1-stream
??? ??? ??? Max AMSDU length: 3839 bytes
??? ??? ??? DSSS/CCK HT40
??? ??? Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
??? ??? Minimum RX AMPDU time spacing: 8 usec (0x06)
??? ??? HT TX/RX MCS rate indexes supported: 0-15
??? ??? Frequencies:
??? ??? ??? * 5180 MHz [36] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5200 MHz [40] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5220 MHz [44] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5240 MHz [48] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5260 MHz [52] (30.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5280 MHz [56] (30.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5300 MHz [60] (30.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5320 MHz [64] (30.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5500 MHz [100] (disabled)
??? ??? ??? * 5520 MHz [104] (disabled)
??? ??? ??? * 5540 MHz [108] (disabled)
??? ??? ??? * 5560 MHz [112] (disabled)
??? ??? ??? * 5580 MHz [116] (disabled)
??? ??? ??? * 5600 MHz [120] (disabled)
??? ??? ??? * 5620 MHz [124] (disabled)
??? ??? ??? * 5640 MHz [128] (disabled)
??? ??? ??? * 5660 MHz [132] (disabled)
??? ??? ??? * 5680 MHz [136] (disabled)
??? ??? ??? * 5700 MHz [140] (disabled)
??? ??? ??? * 5745 MHz [149] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5765 MHz [153] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5785 MHz [157] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5805 MHz [161] (30.0 dBm) (passive scanning, no IBSS)
??? ??? ??? * 5825 MHz [165] (30.0 dBm) (passive scanning, no IBSS)


Atheros Communications Inc. AR928X Wireless Network Adapter:
Band 2:
??? ??? Capabilities: 0x11ce
??? ??? ??? HT20/HT40
??? ??? ??? SM Power Save disabled
??? ??? ??? RX HT40 SGI
??? ??? ??? TX STBC
??? ??? ??? RX STBC 1-stream
??? ??? ??? Max AMSDU length: 7935 bytes
??? ??? ??? DSSS/CCK HT40
??? ??? Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
??? ??? Minimum RX AMPDU time spacing: 8 usec (0x06)
??? ??? HT TX/RX MCS rate indexes supported: 0-15
??? ??? Frequencies:
??? ??? ??? * 5180 MHz [36] (17.0 dBm)
??? ??? ??? * 5200 MHz [40] (17.0 dBm)
??? ??? ??? * 5220 MHz [44] (17.0 dBm)
??? ??? ??? * 5240 MHz [48] (17.0 dBm)
??? ??? ??? * 5260 MHz [52] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5280 MHz [56] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5300 MHz [60] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5320 MHz [64] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5500 MHz [100] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5520 MHz [104] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5540 MHz [108] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5560 MHz [112] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5580 MHz [116] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5600 MHz [120] (disabled)
??? ??? ??? * 5620 MHz [124] (disabled)
??? ??? ??? * 5640 MHz [128] (disabled)
??? ??? ??? * 5660 MHz [132] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5680 MHz [136] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5700 MHz [140] (20.0 dBm) (passive scanning, no IBSS, radar detection)
??? ??? ??? * 5745 MHz [149] (30.0 dBm)
??? ??? ??? * 5765 MHz [153] (30.0 dBm)
??? ??? ??? * 5785 MHz [157] (30.0 dBm)
??? ??? ??? * 5805 MHz [161] (30.0 dBm)
??? ??? ??? * 5825 MHz [165] (30.0 dBm)

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[ath9k-devel] Hardware or software limitation?

[Mihai Moldovan]

Hi Seth,

it is both, really.

Both cards likely have a world roaming regulatory roaming set in their EEPROM
(check dmesg...). On top of that information, restrictions for your current
country are added.

You cannot bypass the card's EEPROM value without hacking the kernel source
(well... with hacking, yes, you could, there is a patch, and I do that as well,
but always within country law.)

Note that "no IBSS" in the iw list output also means "no beaconing" and hence
"no AP mode".


* On 01.08.2012 08:47 PM, Seth Baker wrote:
> I can use 5Ghz AP mode on one, but not the other.
> [...]
>             * 5745 MHz [149] (30.0 dBm)
>             * 5765 MHz [153] (30.0 dBm)
>             * 5785 MHz [157] (30.0 dBm)
>             * 5805 MHz [161] (30.0 dBm)
>             * 5825 MHz [165] (30.0 dBm)

AP mode possible on those 5 channels with the second card, but the first one has
"no IBSS" set on all non-disabled channels (probably due to a preconfigured
world regdom in the EEPROM chip.)

Best regards,


Mihai

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[ath9k-devel] Hardware or software limitation?

[Mihai Moldovan]

* On 03.08.2012 05:24 AM, Seth Baker wrote:
> Yes it makes AP mode not work when EEPROM and crda restrictions
> overlap differently. Can you direct me where to get the patch?

I can only provide you with one for 3.2, latter versions may require editing
(though probably not much.) But I'll assume you know your way around.

You will also need to specify a module parameter when loading ath9k (please
consult your distribution's documentation on how to do this.)

override_eeprom_regdomain=<your country ID here>

The country ID is computed as follows:

> PaulFertser> Get _your_ country code from regd.h, add 32768 and
> supply as a parameter.

Thus, for US, that should be 840 + 32768 = 33608, i.e.,
"override_eeprom_regdomain=33608".

For instance, I'm using "override_eeprom_regdomain=33044" for the German
regulatory entry.

Patch is attached.

Best regards and good luck,


Mihai


P.S.: sorry for the late response, I have to admit to have totally forgotten
about you. :(

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diff -ur linux-3.2-orig/drivers/net/wireless/ath/ath9k/init.c linux-3.2/drivers/net/wireless/ath/ath9k/init.c
--- linux-3.2-orig/drivers/net/wireless/ath/ath9k/init.c	2012-08-03 09:49:22.872823189 +0200
+++ linux-3.2/drivers/net/wireless/ath/ath9k/init.c	2012-08-03 09:58:49.882804322 +0200
@@ -36,6 +36,11 @@
 module_param_named(nohwcrypt, ath9k_modparam_nohwcrypt, int, 0444);
 MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption");
 
+static int modparam_override_eeprom_regdomain = -1;
+module_param_named(override_eeprom_regdomain, 
+                   modparam_override_eeprom_regdomain, int, S_IRUGO);
+MODULE_PARM_DESC(override_eeprom_regdomain, "Override regdomain hardcoded in EEPROM with this value (DANGEROUS).");
+
 int led_blink;
 module_param_named(blink, led_blink, int, 0444);
 MODULE_PARM_DESC(blink, "Enable LED blink on activity");
@@ -666,6 +671,7 @@
 void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
 {
 	struct ath_hw *ah = sc->sc_ah;
+	struct ath_regulatory *regulatory = ath9k_hw_regulatory(sc->sc_ah);
 	struct ath_common *common = ath9k_hw_common(ah);
 
 	hw->flags = IEEE80211_HW_RX_INCLUDES_FCS |
@@ -725,6 +731,14 @@
 		hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
 			&sc->sbands[IEEE80211_BAND_5GHZ];
 
+	if (modparam_override_eeprom_regdomain != -1) {
+		printk(KERN_ERR "ath9k: DANGER! You're overriding EEPROM-defined regulatory domain.\n");
+		printk(KERN_ERR "ath9k: Your card was not certified to operate on the domain you chose.\n");
+		printk(KERN_ERR "ath9k: This might result in a violation of your local regulatory rules.\n");
+		printk(KERN_ERR "ath9k: Do not ever do that unless you really know what you are doing!\n");
+		regulatory->current_rd = modparam_override_eeprom_regdomain;
+	}
+
 	ath9k_reload_chainmask_settings(sc);
 
 	SET_IEEE80211_PERM_ADDR(hw, common->macaddr);
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