From sgruszka@redhat.com Thu Feb  3 07:58:52 2011

Date: Thu, 3 Feb 2011 13:58:51 +0100

From: Stanislaw Gruszka <sgruszka@redhat.com>

To: kernel@lists.fedoraproject.org

Cc: Kyle McMartin <kmcmartin@redhat.com>

Subject: [PATCH F-15] ath5k: fix fast channel change

Message-ID: <20110203125134.GA4515@redhat.com>

From: Nick Kossifidis <mickflemm@gmail.com>

    Fast channel change fixes:

    a) Always set OFDM timings

    b) Don't re-activate PHY

    c) Enable only NF calibration, not AGC

Resolves:

https://bugzilla.redhat.com/show_bug.cgi?id=672778

---

 drivers/net/wireless/ath/ath5k/phy.c |  142 +++++++++++++++++++++-------------

 1 files changed, 87 insertions(+), 55 deletions(-)

diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c

index 78c26fd..d673ab2 100644

--- a/drivers/net/wireless/ath/ath5k/phy.c

+++ b/drivers/net/wireless/ath/ath5k/phy.c

@@ -282,6 +282,34 @@ int ath5k_hw_phy_disable(struct ath5k_hw *ah)

 	return 0;

 }

+/*

+ * Wait for synth to settle

+ */

+static void ath5k_hw_wait_for_synth(struct ath5k_hw *ah,

+			struct ieee80211_channel *channel)

+{

+	/*

+	 * On 5211+ read activation -> rx delay

+	 * and use it (100ns steps).

+	 */

+	if (ah->ah_version != AR5K_AR5210) {

+		u32 delay;

+		delay = ath5k_hw_reg_read(ah, AR5K_PHY_RX_DELAY) &

+			AR5K_PHY_RX_DELAY_M;

+		delay = (channel->hw_value & CHANNEL_CCK) ?

+			((delay << 2) / 22) : (delay / 10);

+		if (ah->ah_bwmode == AR5K_BWMODE_10MHZ)

+			delay = delay << 1;

+		if (ah->ah_bwmode == AR5K_BWMODE_5MHZ)

+			delay = delay << 2;

+		/* XXX: /2 on turbo ? Let's be safe

+		 * for now */

+		udelay(100 + delay);

+	} else {

+		mdelay(1);

+	}

+}

+

 /**********************\

 * RF Gain optimization *

@@ -3237,6 +3265,13 @@ int ath5k_hw_phy_init(struct ath5k_hw *ah, struct ieee80211_channel *channel,

 		/* Failed */

 		if (i >= 100)

 			return -EIO;

+

+		/* Set channel and wait for synth */

+		ret = ath5k_hw_channel(ah, channel);

+		if (ret)

+			return ret;

+

+		ath5k_hw_wait_for_synth(ah, channel);

 	}

 	/*

@@ -3251,13 +3286,53 @@ int ath5k_hw_phy_init(struct ath5k_hw *ah, struct ieee80211_channel *channel,

 	if (ret)

 		return ret;

+	/* Write OFDM timings on 5212*/

+	if (ah->ah_version == AR5K_AR5212 &&

+		channel->hw_value & CHANNEL_OFDM) {

+

+		ret = ath5k_hw_write_ofdm_timings(ah, channel);

+		if (ret)

+			return ret;

+

+		/* Spur info is available only from EEPROM versions

+		 * greater than 5.3, but the EEPROM routines will use

+		 * static values for older versions */

+		if (ah->ah_mac_srev >= AR5K_SREV_AR5424)

+			ath5k_hw_set_spur_mitigation_filter(ah,

+							    channel);

+	}

+

+	/* If we used fast channel switching

+	 * we are done, release RF bus and

+	 * fire up NF calibration.

+	 *

+	 * Note: Only NF calibration due to

+	 * channel change, not AGC calibration

+	 * since AGC is still running !

+	 */

+	if (fast) {

+		/*

+		 * Release RF Bus grant

+		 */

+		AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_RFBUS_REQ,

+				    AR5K_PHY_RFBUS_REQ_REQUEST);

+

+		/*

+		 * Start NF calibration

+		 */

+		AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_AGCCTL,

+					AR5K_PHY_AGCCTL_NF);

+

+		return ret;

+	}

+

 	/*

 	 * For 5210 we do all initialization using

 	 * initvals, so we don't have to modify

 	 * any settings (5210 also only supports

 	 * a/aturbo modes)

 	 */

-	if ((ah->ah_version != AR5K_AR5210) && !fast) {

+	if (ah->ah_version != AR5K_AR5210) {

 		/*

 		 * Write initial RF gain settings

@@ -3276,22 +3351,6 @@ int ath5k_hw_phy_init(struct ath5k_hw *ah, struct ieee80211_channel *channel,

 		if (ret)

 			return ret;

-		/* Write OFDM timings on 5212*/

-		if (ah->ah_version == AR5K_AR5212 &&

-			channel->hw_value & CHANNEL_OFDM) {

-

-			ret = ath5k_hw_write_ofdm_timings(ah, channel);

-			if (ret)

-				return ret;

-

-			/* Spur info is available only from EEPROM versions

-			 * greater than 5.3, but the EEPROM routines will use

-			 * static values for older versions */

-			if (ah->ah_mac_srev >= AR5K_SREV_AR5424)

-				ath5k_hw_set_spur_mitigation_filter(ah,

-								    channel);

-		}

-

 		/*Enable/disable 802.11b mode on 5111

 		(enable 2111 frequency converter + CCK)*/

 		if (ah->ah_radio == AR5K_RF5111) {

@@ -3322,47 +3381,20 @@ int ath5k_hw_phy_init(struct ath5k_hw *ah, struct ieee80211_channel *channel,

 	 */

 	ath5k_hw_reg_write(ah, AR5K_PHY_ACT_ENABLE, AR5K_PHY_ACT);

+	ath5k_hw_wait_for_synth(ah, channel);

+

 	/*

-	 * On 5211+ read activation -> rx delay

-	 * and use it.

+	 * Perform ADC test to see if baseband is ready

+	 * Set tx hold and check adc test register

 	 */

-	if (ah->ah_version != AR5K_AR5210) {

-		u32 delay;

-		delay = ath5k_hw_reg_read(ah, AR5K_PHY_RX_DELAY) &

-			AR5K_PHY_RX_DELAY_M;

-		delay = (channel->hw_value & CHANNEL_CCK) ?

-			((delay << 2) / 22) : (delay / 10);

-		if (ah->ah_bwmode == AR5K_BWMODE_10MHZ)

-			delay = delay << 1;

-		if (ah->ah_bwmode == AR5K_BWMODE_5MHZ)

-			delay = delay << 2;

-		/* XXX: /2 on turbo ? Let's be safe

-		 * for now */

-		udelay(100 + delay);

-	} else {

-		mdelay(1);

-	}

-

-	if (fast)

-		/*

-		 * Release RF Bus grant

-		 */

-		AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_RFBUS_REQ,

-				    AR5K_PHY_RFBUS_REQ_REQUEST);

-	else {

-		/*

-		 * Perform ADC test to see if baseband is ready

-		 * Set tx hold and check adc test register

-		 */

-		phy_tst1 = ath5k_hw_reg_read(ah, AR5K_PHY_TST1);

-		ath5k_hw_reg_write(ah, AR5K_PHY_TST1_TXHOLD, AR5K_PHY_TST1);

-		for (i = 0; i <= 20; i++) {

-			if (!(ath5k_hw_reg_read(ah, AR5K_PHY_ADC_TEST) & 0x10))

-				break;

-			udelay(200);

-		}

-		ath5k_hw_reg_write(ah, phy_tst1, AR5K_PHY_TST1);

+	phy_tst1 = ath5k_hw_reg_read(ah, AR5K_PHY_TST1);

+	ath5k_hw_reg_write(ah, AR5K_PHY_TST1_TXHOLD, AR5K_PHY_TST1);

+	for (i = 0; i <= 20; i++) {

+		if (!(ath5k_hw_reg_read(ah, AR5K_PHY_ADC_TEST) & 0x10))

+			break;

+		udelay(200);

 	}

+	ath5k_hw_reg_write(ah, phy_tst1, AR5K_PHY_TST1);

 	/*

 	 * Start automatic gain control calibration