openwrt/package/kernel/mac80211/patches/ath9k/351-ath9k_hw-issue-external-reset-for-QCA955x.patch

From: Felix Fietkau <nbd@nbd.name>
Date: Sat, 9 Jul 2016 15:26:44 +0200
Subject: [PATCH] ath9k_hw: issue external reset for QCA955x

The RTC interface on the SoC needs to be reset along with the rest of
the WMAC.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1311,39 +1311,56 @@ void ath9k_hw_get_delta_slope_vals(struc
 	*coef_exponent = coef_exp - 16;
 }
 
-/* AR9330 WAR:
- * call external reset function to reset WMAC if:
- * - doing a cold reset
- * - we have pending frames in the TX queues.
- */
-static bool ath9k_hw_ar9330_reset_war(struct ath_hw *ah, int type)
+static bool ath9k_hw_need_external_reset(struct ath_hw *ah, int type)
 {
-	int i, npend = 0;
+	int i;
 
-	for (i = 0; i < AR_NUM_QCU; i++) {
-		npend = ath9k_hw_numtxpending(ah, i);
-		if (npend)
-			break;
-	}
-
-	if (ah->external_reset &&
-	    (npend || type == ATH9K_RESET_COLD)) {
-		int reset_err = 0;
-
-		ath_dbg(ath9k_hw_common(ah), RESET,
-			"reset MAC via external reset\n");
-
-		reset_err = ah->external_reset();
-		if (reset_err) {
-			ath_err(ath9k_hw_common(ah),
-				"External reset failed, err=%d\n",
-				reset_err);
-			return false;
+	if (type == ATH9K_RESET_COLD)
+		return true;
+
+	if (AR_SREV_9550(ah))
+		return true;
+
+	/* AR9330 WAR:
+	 * call external reset function to reset WMAC if:
+	 * - doing a cold reset
+	 * - we have pending frames in the TX queues.
+	 */
+	if (AR_SREV_9330(ah)) {
+		for (i = 0; i < AR_NUM_QCU; i++) {
+			if (ath9k_hw_numtxpending(ah, i))
+				return true;
 		}
+	}
+
+	return false;
+}
+
+static bool ath9k_hw_external_reset(struct ath_hw *ah, int type)
+{
+	int err;
+
+	if (!ah->external_reset || !ath9k_hw_need_external_reset(ah, type))
+		return true;
+
+	ath_dbg(ath9k_hw_common(ah), RESET,
+		"reset MAC via external reset\n");
 
-		REG_WRITE(ah, AR_RTC_RESET(ah), 1);
+	err = ah->external_reset();
+	if (err) {
+		ath_err(ath9k_hw_common(ah),
+			"External reset failed, err=%d\n", err);
+		return false;
 	}
 
+	if (AR_SREV_9550(ah)) {
+		REG_WRITE(ah, AR_RTC_RESET(ah), 0);
+		udelay(10);
+	}
+
+	REG_WRITE(ah, AR_RTC_RESET(ah), 1);
+	udelay(10);
+
 	return true;
 }
 
@@ -1396,24 +1413,24 @@ static bool ath9k_hw_set_reset(struct at
 			rst_flags |= AR_RTC_RC_MAC_COLD;
 	}
 
-	if (AR_SREV_9330(ah)) {
-		if (!ath9k_hw_ar9330_reset_war(ah, type))
-			return false;
-	}
-
 	if (ath9k_hw_mci_is_enabled(ah))
 		ar9003_mci_check_gpm_offset(ah);
 
 	/* DMA HALT added to resolve ar9300 and ar9580 bus error during
-	 * RTC_RC reg read
+	 * RTC_RC reg read. Also needed for AR9550 external reset
 	 */
-	if (AR_SREV_9300(ah) || AR_SREV_9580(ah)) {
+	if (AR_SREV_9300(ah) || AR_SREV_9580(ah) || AR_SREV_9550(ah)) {
 		REG_SET_BIT(ah, AR_CFG, AR_CFG_HALT_REQ);
 		ath9k_hw_wait(ah, AR_CFG, AR_CFG_HALT_ACK, AR_CFG_HALT_ACK,
 			      20 * AH_WAIT_TIMEOUT);
-		REG_CLR_BIT(ah, AR_CFG, AR_CFG_HALT_REQ);
 	}
 
+	if (!AR_SREV_9100(ah))
+		ath9k_hw_external_reset(ah, type);
+
+	if (AR_SREV_9300(ah) || AR_SREV_9580(ah))
+		REG_CLR_BIT(ah, AR_CFG, AR_CFG_HALT_REQ);
+
 	REG_WRITE(ah, AR_RTC_RC(ah), rst_flags);
 
 	REGWRITE_BUFFER_FLUSH(ah);