[PATCH] cfg80211: adapt to new channelization of the 6GHz band

[PATCH] cfg80211: adapt to new channelization of the 6GHz band

[Arend Van Spriel]

The 6GHz band does not have regulatory approval yet, but things are
moving forward. However, that has led to a change in the channelization
of the 6GHz band which has been accepted in the 11ax specification.

This change is primarily thrown in to discuss how to deal with it.
I noticed ath11k adding 6G support with old channelization and ditto
for iw. It probably involves changes in hostapd as well.

Cc: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Cc: Jouni Malinen <jouni@w1.fi>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
  net/wireless/util.c | 43 ++++++++++++++++++++++++++++++++++++++-----
  1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index df75e58eca5d..f0a3a021ee0d 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -92,9 +92,11 @@ u32 ieee80211_channel_to_freq_khz(int chan, enum 
nl80211_band band)
  			return MHZ_TO_KHZ(5000 + chan * 5);
  		break;
  	case NL80211_BAND_6GHZ:
-		/* see 802.11ax D4.1 27.3.22.2 */
+		/* see 802.11ax D6.1 27.3.23.2 */
+		if (chan == 2)
+			return MHZ_TO_KHZ(5935);
  		if (chan <= 253)
-			return 5940 + chan * 5;
+			return MHZ_TO_KHZ(5950 + chan * 5);
  		break;
  	case NL80211_BAND_60GHZ:
  		if (chan < 7)
@@ -119,11 +121,14 @@ int ieee80211_freq_khz_to_channel(u32 freq)
  		return (freq - 2407) / 5;
  	else if (freq >= 4910 && freq <= 4980)
  		return (freq - 4000) / 5;
-	else if (freq < 5945)
+	else if (freq < 5935)
  		return (freq - 5000) / 5;
+	else if (freq == 5935)
+		/* see 802.11ax D6.1 27.3.23.2 */
+		return 2;
  	else if (freq <= 45000) /* DMG band lower limit */
-		/* see 802.11ax D4.1 27.3.22.2 */
-		return (freq - 5940) / 5;
+		/* see 802.11ax D6.1 27.3.23.2 */
+		return (freq - 5950) / 5;
  	else if (freq >= 58320 && freq <= 70200)
  		return (freq - 56160) / 2160;
  	else
@@ -1662,6 +1667,34 @@ bool ieee80211_chandef_to_operating_class(struct 
cfg80211_chan_def *chandef,
  		return true;
  	}
+	/* 6GHz, channels 1..233 */
+	if (freq >= 5935 && freq <= 7115) {
+		switch (chandef->width) {
+		case NL80211_CHAN_WIDTH_20:
+			*op_class = 131;
+			break;
+		case NL80211_CHAN_WIDTH_40:
+			*op_class = 132;
+			break;
+		case NL80211_CHAN_WIDTH_80:
+			*op_class = 133;
+			break;
+		case NL80211_CHAN_WIDTH_160:
+			*op_class = 134;
+			break;
+		case NL80211_CHAN_WIDTH_80P80:
+			*op_class = 135;
+			break;
+		case NL80211_CHAN_WIDTH_5:
+		case NL80211_CHAN_WIDTH_10:
+		case NL80211_CHAN_WIDTH_20_NOHT:
+		default:
+			return false;
+		}
+
+		return true;
+	}
+
  	/* 56.16 GHz, channel 1..4 */
  	if (freq >= 56160 + 2160 * 1 && freq <= 56160 + 2160 * 6) {
  		if (chandef->width >= NL80211_CHAN_WIDTH_40)
-- 
2.18.0

Re: [PATCH] cfg80211: adapt to new channelization of the 6GHz band

[Johannes Berg]

On Fri, 2020-05-29 at 10:16 +0200, Arend Van Spriel wrote:
> The 6GHz band does not have regulatory approval yet, but things are
> moving forward. However, that has led to a change in the channelization
> of the 6GHz band which has been accepted in the 11ax specification.
> 
>   	case NL80211_BAND_6GHZ:
> -		/* see 802.11ax D4.1 27.3.22.2 */
> +		/* see 802.11ax D6.1 27.3.23.2 */
> +		if (chan == 2)
> +			return MHZ_TO_KHZ(5935);

I think Jouni said this was operating class 136?

> +	/* 6GHz, channels 1..233 */
> +	if (freq >= 5935 && freq <= 7115) {
> +		switch (chandef->width) {
> +		case NL80211_CHAN_WIDTH_20:
> +			*op_class = 131;
> +			break;
> +		case NL80211_CHAN_WIDTH_40:
> +			*op_class = 132;
> +			break;
> +		case NL80211_CHAN_WIDTH_80:
> +			*op_class = 133;
> +			break;
> +		case NL80211_CHAN_WIDTH_160:
> +			*op_class = 134;
> +			break;
> +		case NL80211_CHAN_WIDTH_80P80:
> +			*op_class = 135;
> +			break;
> +		case NL80211_CHAN_WIDTH_5:
> +		case NL80211_CHAN_WIDTH_10:
> +		case NL80211_CHAN_WIDTH_20_NOHT:
> +		default:
> +			return false;
> +		}

If so, isn't that missing here?

johannes

Re: [PATCH] cfg80211: adapt to new channelization of the 6GHz band

[Arend Van Spriel]

On 5/29/2020 10:19 AM, Johannes Berg wrote:
> On Fri, 2020-05-29 at 10:16 +0200, Arend Van Spriel wrote:
>> The 6GHz band does not have regulatory approval yet, but things are
>> moving forward. However, that has led to a change in the channelization
>> of the 6GHz band which has been accepted in the 11ax specification.
>>
>>    	case NL80211_BAND_6GHZ:
>> -		/* see 802.11ax D4.1 27.3.22.2 */
>> +		/* see 802.11ax D6.1 27.3.23.2 */
>> +		if (chan == 2)
>> +			return MHZ_TO_KHZ(5935);
> 
> I think Jouni said this was operating class 136?
> 
>> +	/* 6GHz, channels 1..233 */
>> +	if (freq >= 5935 && freq <= 7115) {
>> +		switch (chandef->width) {
>> +		case NL80211_CHAN_WIDTH_20:
>> +			*op_class = 131;
>> +			break;
>> +		case NL80211_CHAN_WIDTH_40:
>> +			*op_class = 132;
>> +			break;
>> +		case NL80211_CHAN_WIDTH_80:
>> +			*op_class = 133;
>> +			break;
>> +		case NL80211_CHAN_WIDTH_160:
>> +			*op_class = 134;
>> +			break;
>> +		case NL80211_CHAN_WIDTH_80P80:
>> +			*op_class = 135;
>> +			break;
>> +		case NL80211_CHAN_WIDTH_5:
>> +		case NL80211_CHAN_WIDTH_10:
>> +		case NL80211_CHAN_WIDTH_20_NOHT:
>> +		default:
>> +			return false;
>> +		}
> 
> If so, isn't that missing here?

At least should indeed take it into account here. However I can not get 
my hands on the 6.1 spec (yet). I have the document with editor 
instructions and operating class for channel 2 is marked as <ANA> in 
table Annex E-4. 136 would be the logical value, but without the 6.1 
spec I am not sure. I will resend the patch.

Regards,
Arend