ath9k_hw: Update the PCI WAR register

This patch updates the PCI power save handling
code, fixing ASPM hangs and handling device state D3
properly.

The WAR register is programmed with the correct
values now.

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

2 files changed, 60 insertions, 28 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9002_hw.c b/drivers/net/wireless/ath/ath9k/ar9002_hw.c
index a8a8cdc04af..748449cd587 100644
--- a/drivers/net/wireless/ath/ath9k/ar9002_hw.c
+++ b/drivers/net/wireless/ath/ath9k/ar9002_hw.c
@@ -436,55 +436,84 @@ static void ar9002_hw_configpcipowersave(struct ath_hw *ah,
 		}
 
 		udelay(1000);
+	}
 
-		/* set bit 19 to allow forcing of pcie core into L1 state */
-		REG_SET_BIT(ah, AR_PCIE_PM_CTRL, AR_PCIE_PM_CTRL_ENA);
+	if (power_off) {
+		/* clear bit 19 to disable L1 */
+		REG_CLR_BIT(ah, AR_PCIE_PM_CTRL, AR_PCIE_PM_CTRL_ENA);
+
+		val = REG_READ(ah, AR_WA);
 
-		/* Several PCIe massages to ensure proper behaviour */
+		/*
+		 * Set PCIe workaround bits
+		 * In AR9280 and AR9285, bit 14 in WA register (disable L1)
+		 * should only  be set when device enters D3 and be
+		 * cleared when device comes back to D0.
+		 */
+		if (ah->config.pcie_waen) {
+			if (ah->config.pcie_waen & AR_WA_D3_L1_DISABLE)
+				val |= AR_WA_D3_L1_DISABLE;
+		} else {
+			if (((AR_SREV_9285(ah) ||
+			      AR_SREV_9271(ah) ||
+			      AR_SREV_9287(ah)) &&
+			     (AR9285_WA_DEFAULT & AR_WA_D3_L1_DISABLE)) ||
+			    (AR_SREV_9280(ah) &&
+			     (AR9280_WA_DEFAULT & AR_WA_D3_L1_DISABLE))) {
+				val |= AR_WA_D3_L1_DISABLE;
+			}
+		}
+
+		if (AR_SREV_9280(ah) || AR_SREV_9285(ah) || AR_SREV_9287(ah)) {
+			/*
+			 * Disable bit 6 and 7 before entering D3 to
+			 * prevent system hang.
+			 */
+			val &= ~(AR_WA_BIT6 | AR_WA_BIT7);
+		}
+
+		if (AR_SREV_9285E_20(ah))
+			val |= AR_WA_BIT23;
+
+		REG_WRITE(ah, AR_WA, val);
+	} else {
 		if (ah->config.pcie_waen) {
 			val = ah->config.pcie_waen;
 			if (!power_off)
 				val &= (~AR_WA_D3_L1_DISABLE);
 		} else {
-			if (AR_SREV_9285(ah) || AR_SREV_9271(ah) ||
+			if (AR_SREV_9285(ah) ||
+			    AR_SREV_9271(ah) ||
 			    AR_SREV_9287(ah)) {
 				val = AR9285_WA_DEFAULT;
 				if (!power_off)
 					val &= (~AR_WA_D3_L1_DISABLE);
-			} else if (AR_SREV_9280(ah)) {
+			}
+			else if (AR_SREV_9280(ah)) {
 				/*
-				 * On AR9280 chips bit 22 of 0x4004 needs to be
-				 * set otherwise card may disappear.
+				 * For AR9280 chips, bit 22 of 0x4004
+				 * needs to be set.
 				 */
 				val = AR9280_WA_DEFAULT;
 				if (!power_off)
 					val &= (~AR_WA_D3_L1_DISABLE);
-			} else
+			} else {
 				val = AR_WA_DEFAULT;
+			}
+		}
+
+		/* WAR for ASPM system hang */
+		if (AR_SREV_9280(ah) || AR_SREV_9285(ah) || AR_SREV_9287(ah)) {
+			val |= (AR_WA_BIT6 | AR_WA_BIT7);
 		}
 
+		if (AR_SREV_9285E_20(ah))
+			val |= AR_WA_BIT23;
+
 		REG_WRITE(ah, AR_WA, val);
-	}
 
-	if (power_off) {
-		/*
-		 * Set PCIe workaround bits
-		 * bit 14 in WA register (disable L1) should only
-		 * be set when device enters D3 and be cleared
-		 * when device comes back to D0.
-		 */
-		if (ah->config.pcie_waen) {
-			if (ah->config.pcie_waen & AR_WA_D3_L1_DISABLE)
-				REG_SET_BIT(ah, AR_WA, AR_WA_D3_L1_DISABLE);
-		} else {
-			if (((AR_SREV_9285(ah) || AR_SREV_9271(ah) ||
-			      AR_SREV_9287(ah)) &&
-			     (AR9285_WA_DEFAULT & AR_WA_D3_L1_DISABLE)) ||
-			    (AR_SREV_9280(ah) &&
-			     (AR9280_WA_DEFAULT & AR_WA_D3_L1_DISABLE))) {
-				REG_SET_BIT(ah, AR_WA, AR_WA_D3_L1_DISABLE);
-			}
-		}
+		/* set bit 19 to allow forcing of pcie core into L1 state */
+		REG_SET_BIT(ah, AR_PCIE_PM_CTRL, AR_PCIE_PM_CTRL_ENA);
 	}
 }
 
diff --git a/drivers/net/wireless/ath/ath9k/reg.h b/drivers/net/wireless/ath/ath9k/reg.h
index c9a009fab22..a7371a08049 100644
--- a/drivers/net/wireless/ath/ath9k/reg.h
+++ b/drivers/net/wireless/ath/ath9k/reg.h
@@ -700,6 +700,9 @@
 #define AR_RC_HOSTIF         0x00000100
 
 #define AR_WA                		0x4004
+#define AR_WA_BIT6			(1 << 6)
+#define AR_WA_BIT7			(1 << 7)
+#define AR_WA_BIT23			(1 << 23)
 #define AR_WA_D3_L1_DISABLE		(1 << 14)
 #define AR9285_WA_DEFAULT		0x004a050b
 #define AR9280_WA_DEFAULT           	0x0040073b