ath9k_hw: fix ASPM setting for AR9003

The AR_WA register should not be read when in sleep state so
add a variable we can stash its value into for when we need
to set it. Additionally the AR_WA_D3_TO_L1_DISABLE_REAL
(bit 16) needs to be removed.

Cc: Aeolus Yang <aeolus.yang@atheros.com>
Cc: Madhan Jaganathan <madhan.jaganathan@atheros.com>
signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 39 insertions, 6 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 62597f4ca319..fb09042e2889 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -575,14 +575,8 @@ static int __ath9k_hw_init(struct ath_hw *ah)
          * This enables PCIe low power mode.
          */
         if (AR_SREV_9300_20_OR_LATER(ah)) {
-                u32 regval;
                 unsigned int i;
 
-                /* Set Bits 16 and 17 in the AR_WA register. */
-                regval = REG_READ(ah, AR_WA);
-                regval |= 0x00030000;
-                REG_WRITE(ah, AR_WA, regval);
-
                 for (i = 0; i < ah->iniPcieSerdesLowPower.ia_rows; i++) {
                         REG_WRITE(ah,
                                   INI_RA(&ah->iniPcieSerdesLowPower, i, 0),
@@ -590,6 +584,15 @@ static int __ath9k_hw_init(struct ath_hw *ah)
                 }
         }
 
+        /*
+         * Read back AR_WA into a permanent copy and set bits 14 and 17.
+         * We need to do this to avoid RMW of this register. We cannot
+         * read the reg when chip is asleep.
+         */
+        ah->WARegVal = REG_READ(ah, AR_WA);
+        ah->WARegVal |= (AR_WA_D3_L1_DISABLE |
+                         AR_WA_ASPM_TIMER_BASED_DISABLE);
+
         if (ah->is_pciexpress)
                 ath9k_hw_configpcipowersave(ah, 0, 0);
         else
@@ -1009,6 +1012,11 @@ static bool ath9k_hw_set_reset(struct ath_hw *ah, int type)
 
         ENABLE_REGWRITE_BUFFER(ah);
 
+        if (AR_SREV_9300_20_OR_LATER(ah)) {
+                REG_WRITE(ah, AR_WA, ah->WARegVal);
+                udelay(10);
+        }
+
         REG_WRITE(ah, AR_RTC_FORCE_WAKE, AR_RTC_FORCE_WAKE_EN |
                   AR_RTC_FORCE_WAKE_ON_INT);
 
@@ -1063,6 +1071,11 @@ static bool ath9k_hw_set_reset_power_on(struct ath_hw *ah)
 {
         ENABLE_REGWRITE_BUFFER(ah);
 
+        if (AR_SREV_9300_20_OR_LATER(ah)) {
+                REG_WRITE(ah, AR_WA, ah->WARegVal);
+                udelay(10);
+        }
+
         REG_WRITE(ah, AR_RTC_FORCE_WAKE, AR_RTC_FORCE_WAKE_EN |
                   AR_RTC_FORCE_WAKE_ON_INT);
 
@@ -1099,6 +1112,11 @@ static bool ath9k_hw_set_reset_power_on(struct ath_hw *ah)
 
 static bool ath9k_hw_set_reset_reg(struct ath_hw *ah, u32 type)
 {
+        if (AR_SREV_9300_20_OR_LATER(ah)) {
+                REG_WRITE(ah, AR_WA, ah->WARegVal);
+                udelay(10);
+        }
+
         REG_WRITE(ah, AR_RTC_FORCE_WAKE,
                   AR_RTC_FORCE_WAKE_EN | AR_RTC_FORCE_WAKE_ON_INT);
 
@@ -1768,6 +1786,11 @@ static void ath9k_set_power_sleep(struct ath_hw *ah, int setChip)
                         REG_CLR_BIT(ah, (AR_RTC_RESET),
                                     AR_RTC_RESET_EN);
         }
+
+        /* Clear Bit 14 of AR_WA after putting chip into Full Sleep mode. */
+        if (AR_SREV_9300_20_OR_LATER(ah))
+                REG_WRITE(ah, AR_WA,
+                          ah->WARegVal & ~AR_WA_D3_L1_DISABLE);
 }
 
 /*
@@ -1794,6 +1817,10 @@ static void ath9k_set_power_network_sleep(struct ath_hw *ah, int setChip)
                                     AR_RTC_FORCE_WAKE_EN);
                 }
         }
+
+        /* Clear Bit 14 of AR_WA after putting chip into Net Sleep mode. */
+        if (AR_SREV_9300_20_OR_LATER(ah))
+                REG_WRITE(ah, AR_WA, ah->WARegVal & ~AR_WA_D3_L1_DISABLE);
 }
 
 static bool ath9k_hw_set_power_awake(struct ath_hw *ah, int setChip)
@@ -1801,6 +1828,12 @@ static bool ath9k_hw_set_power_awake(struct ath_hw *ah, int setChip)
         u32 val;
         int i;
 
+        /* Set Bits 14 and 17 of AR_WA before powering on the chip. */
+        if (AR_SREV_9300_20_OR_LATER(ah)) {
+                REG_WRITE(ah, AR_WA, ah->WARegVal);
+                udelay(10);
+        }
+
         if (setChip) {
                 if ((REG_READ(ah, AR_RTC_STATUS) &
                      AR_RTC_STATUS_M) == AR_RTC_STATUS_SHUTDOWN) {