ath5k: Fix fast channel switching

Fast channel change fixes:

a) Always set OFDM timings
b) Don't re-activate PHY
c) Enable only NF calibration, not AGC

https://bugzilla.kernel.org/show_bug.cgi?id=27382

Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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 c44111fc98b7..62ce2f4e8605 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 *
@@ -3238,6 +3266,13 @@ 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);
         }
 
         /*
@@ -3252,13 +3287,53 @@ 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
@@ -3277,22 +3352,6 @@ 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) {
@@ -3323,47 +3382,20 @@ 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