ath9k_hw: read and backup AR_WA register value even before chip reset on.

We need to read and backup AR_WA register value permanently and reading
this after the chip is awakened results in this register being zeroed out.

This seems to fix the ASPM with L1 enabled issue that we have observed.
The laptop becomes very slow and hangs mostly with ASPM L1 enabled without
this fix.

Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index c0838c216aab73463583ed6d51e6a84829a1c09a..bc92b4579b27effcf519fd7241aace2646011ca7 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -494,6 +494,15 @@ static int __ath9k_hw_init(struct ath_hw *ah)
 
        ath9k_hw_read_revisions(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 (!ath9k_hw_set_reset_reg(ah, ATH9K_RESET_POWER_ON)) {
                ath_err(common, "Couldn't reset chip\n");
                return -EIO;
@@ -562,14 +571,6 @@ static int __ath9k_hw_init(struct ath_hw *ah)
 
        ath9k_hw_init_mode_regs(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);