Atheros ART power limit bypass, linux regulatory will be applied (e.g.: iw phy phy0 set txpower fixed 3100)

800-ath9k-bypass-eeprom-power.patch

--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -5142,6 +5142,11 @@ static void ar9003_hw_set_power_per_rate
 	scaledPower = ath9k_hw_get_scaled_power(ah, powerLimit,
 						antenna_reduction);
 
+	minCtlPower = (u8) min(MAX_RATE_POWER, scaledPower);
+	for (i = 0; i < ar9300RateSize; i++)
+		pPwrArray[i] = (u8) minCtlPower;
+	return;
+
 	if (is2ghz) {
 		/* Setup for CTL modes */
 		/* CTL_11B, CTL_11G, CTL_2GHT20 */

ar9003_eeprom_power_mod.c

static void ar9003_hw_set_power_per_rate_table(struct ath_hw *ah,
					       struct ath9k_channel *chan,
					       u8 *pPwrArray, u16 cfgCtl,
					       u8 antenna_reduction,
					       u16 powerLimit)
{
	struct ath_common *common = ath9k_hw_common(ah);
	struct ar9300_eeprom *pEepData = &ah->eeprom.ar9300_eep;
	u16 twiceMaxEdgePower;
	int i;
	u16 scaledPower = 0, minCtlPower;
	static const u16 ctlModesFor11a[] = {
		CTL_11A, CTL_5GHT20, CTL_11A_EXT, CTL_5GHT40
	};
	static const u16 ctlModesFor11g[] = {
		CTL_11B, CTL_11G, CTL_2GHT20, CTL_11B_EXT,
		CTL_11G_EXT, CTL_2GHT40
	};
	u16 numCtlModes;
	const u16 *pCtlMode;
	u16 ctlMode, freq;
	struct chan_centers centers;
	u8 *ctlIndex;
	u8 ctlNum;
	u16 twiceMinEdgePower;
	bool is2ghz = IS_CHAN_2GHZ(chan);

	ath9k_hw_get_channel_centers(ah, chan, &centers);
	scaledPower = ath9k_hw_get_scaled_power(ah, powerLimit,
						antenna_reduction);
  
  	minCtlPower = (u8) min(MAX_RATE_POWER, scaledPower);   // [MOD]
	for (i = 0; i < ar9300RateSize; i++)                   // [MOD]
		pPwrArray[i] = (u8) minCtlPower;               // [MOD]
	return;                                                // [MOD]
  
	if (is2ghz) {

// [...]

LEDE instruction:

1. Clone LEDE project
   git clone https://github.com/lede-project/source.git
cd source

2. Build for your target
   make menuconfig (select your target)
   make package/kernel/mac80211/compile

3. Patch the driver with my diff
   You have to edit ar9003_hw_set_power_per_rate_table function in this file:
   build_dir/target-[ARCH]/linux-ar71xx_generic/backports-[VER]/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
   (Add lines with // [MOD] comment)

4. Build and flash the firmware
   Build the firmware
   make -j9
   (Where 9 is your cpu's threads number + 1)
   Then flash the router
   On PC: nc -l -p 1234 -q 0 < bin/targets/ar71xx/generic/lede-ar71xx-generic-[MODEL]-squashfs-sysupgrade.bin
   On router: nc 192.168.1.X 1234 > /tmp/fw.bin && sysupgrade /tmp/fw.bin

5. Set the power
   After the router reboot:
   iw phy phy0 set txpower fixed 3100
   and then check the power:
   iwinfo phy0 txpower
   You should see

   0 dBm (   1 mW)
   1 dBm (   1 mW)
   2 dBm (   1 mW)
   3 dBm (   1 mW)
   4 dBm (   2 mW)
   5 dBm (   3 mW)
   6 dBm (   3 mW)
   7 dBm (   5 mW)
   8 dBm (   6 mW)
   9 dBm (   7 mW)
  10 dBm (  10 mW)
  11 dBm (  12 mW)
  12 dBm (  15 mW)
  13 dBm (  19 mW)
  14 dBm (  25 mW)
  15 dBm (  31 mW)
  16 dBm (  39 mW)
  17 dBm (  50 mW)
  18 dBm (  63 mW)
  19 dBm (  79 mW)
  20 dBm ( 100 mW)
  21 dBm ( 125 mW)
  22 dBm ( 158 mW)
  23 dBm ( 199 mW)
  24 dBm ( 251 mW)
  25 dBm ( 316 mW)
  26 dBm ( 398 mW)
  27 dBm ( 501 mW)
  28 dBm ( 630 mW)
  29 dBm ( 794 mW)
  30 dBm (1000 mW)
* 31 dBm (1258 mW)

I tested this mod with an instrument, at ~50 cm of distance from the antennas:

• 20 dBm --> 8 volt/meter [original max power]
• 25 dBm --> 17 volt/meter
• 31 dBm --> more than 30 volt/meter

Hey, if i dont want to compile the whole image, is it possible to compile it with make -j5 package/kernel/mac80211/compile
and install one of the kmod-ath*.ipk ?
./bin/targets/ath79/generic/packages/kmod-ath9k-common_5.4.52+5.8-1-1_mips_24kc.ipk
./bin/targets/ath79/generic/packages/kmod-ath9k_5.4.52+5.8-1-1_mips_24kc.ipk
./bin/targets/ath79/generic/packages/kmod-ath_5.4.52+5.8-1-1_mips_24kc.ipk
Which one is the right?

kmod-ath9k_5.4.52+5.8-1-1_mips_24kc.ipk is working fine, but some channels on 5 ghz are only 14 dBm
44, 48, 52, 56, 60, 64
is there a way to fix that?