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>

diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c
index c44111f..62ce2f4 100644 (file)
--- 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