wifi-scripts: fix missing VHT capabilities detection

* Add missing parentheses in the conditionals for VHT160/VHT160-80PLUS80
  and VHT_MAX_MPDU capabilities. The missing parentheses caused the bitwise
  AND to be evaluated after the equality comparison due to ECMA's operator
  precedence, where `==` has higher precedence than `&`.

* Fix Max MPDU length detection by changing the comparison operators to
  `>=` vs `>` otherwise the condition would never be met.

* Add missing default values:
  - `true` value for `short_gi_80` (As it exists for `short_gi_20`, `short_gi_40`, `short_gi_160`)
  - `7` for `vht_max_mpdu` (Without it the loop in MAX-MPDU-* calculation always compares with null)

* Change the `vht160` condition to `config.vht160 <= 2`. This flag is
  `2` by default, and only ever set to `0` when `vht_oper_chwidth < 2`.

Signed-off-by: Sean Khan <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/18013
Signed-off-by: John Crispin <[email protected]>

package/network/config/wifi-scripts/files-ucode/usr/share/schema/wireless.wifi-device.json

@@ -635,7 +635,8 @@
 		},
 		"short_gi_80": {
 			"description": "Short GI for 80 MHz",
-			"type": "boolean"
+			"type": "boolean",
+			"default": true
 		},
 		"spectrum_mgmt_required": {
 			"description": "Set Spectrum Management subfield in the Capability Information field",
@@ -712,7 +713,8 @@
 			"description": "Indicates the maximum length of A-MPDU pre-EOF padding that the STA can recv",
 			"type": "number",
 			"minimum": 0,
-			"maximum": 7
+			"maximum": 7,
+			"default": 7
 		},
 		"vht_max_mpdu": {
 			"description": "Maximum MPDU length",

package/network/config/wifi-scripts/files-ucode/usr/share/ucode/wifi/hostapd.uc

@@ -338,15 +338,15 @@ function device_htmode_append(config) {
 			config.vht_capab += '[BF-ANTENNA-' + min(((vht_capab >> 13) & 3) + 1, config.beamformer_antennas) + ']';
 
 		/* supported Channel widths */
-		if (vht_capab & 0xc == 8 && config.vht160 <= 2)
+		if ((vht_capab & 0xc) == 8 && config.vht160 <= 2)
 			config.vht_capab += '[VHT160-80PLUS80]';
-		else if (vht_capab & 0xc == 4 && config.vht160 <= 1)
+		else if ((vht_capab & 0xc) == 4 && config.vht160 <= 2)
 			config.vht_capab += '[VHT160]';
 
 		/* maximum MPDU length */
-		if (vht_capab & 3 > 1 && config.vht_max_mpdu > 11454)
+		if ((vht_capab & 3) > 1 && config.vht_max_mpdu >= 11454)
 			config.vht_capab += '[MAX-MPDU-11454]';
-		else if (vht_capab & 3 && config.vht_max_mpdu > 7991)
+		else if ((vht_capab & 3) && config.vht_max_mpdu >= 7991)
 			config.vht_capab += '[MAX-MPDU-7991]';
 
 		/* maximum A-MPDU length exponent */