From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752084AbaBLIOD (ORCPT ); Wed, 12 Feb 2014 03:14:03 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50141 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752030AbaBLIN6 (ORCPT ); Wed, 12 Feb 2014 03:13:58 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Sujith Manoharan" , "John W. Linville" , "Felix Fietkau" Date: Wed, 12 Feb 2014 08:10:12 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 50/79] ath9k: Fix interrupt handling for the AR9002 family In-Reply-To: X-SA-Exim-Connect-IP: 91.84.160.45 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.55-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Sujith Manoharan commit 73f0b56a1ff64e7fb6c3a62088804bab93bcedc2 upstream. This patch adds a driver workaround for a HW issue. A race condition in the HW results in missing interrupts, which can be avoided by a read/write with the ISR register. All chips in the AR9002 series are affected by this bug - AR9003 and above do not have this problem. Cc: Felix Fietkau Signed-off-by: Sujith Manoharan Signed-off-by: John W. Linville Signed-off-by: Ben Hutchings --- drivers/net/wireless/ath/ath9k/ar9002_mac.c | 52 ++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 9 deletions(-) --- a/drivers/net/wireless/ath/ath9k/ar9002_mac.c +++ b/drivers/net/wireless/ath/ath9k/ar9002_mac.c @@ -76,9 +76,16 @@ static bool ar9002_hw_get_isr(struct ath mask2 |= ATH9K_INT_CST; if (isr2 & AR_ISR_S2_TSFOOR) mask2 |= ATH9K_INT_TSFOOR; + + if (!(pCap->hw_caps & ATH9K_HW_CAP_RAC_SUPPORTED)) { + REG_WRITE(ah, AR_ISR_S2, isr2); + isr &= ~AR_ISR_BCNMISC; + } } - isr = REG_READ(ah, AR_ISR_RAC); + if (pCap->hw_caps & ATH9K_HW_CAP_RAC_SUPPORTED) + isr = REG_READ(ah, AR_ISR_RAC); + if (isr == 0xffffffff) { *masked = 0; return false; @@ -97,11 +104,23 @@ static bool ar9002_hw_get_isr(struct ath *masked |= ATH9K_INT_TX; - s0_s = REG_READ(ah, AR_ISR_S0_S); + if (pCap->hw_caps & ATH9K_HW_CAP_RAC_SUPPORTED) { + s0_s = REG_READ(ah, AR_ISR_S0_S); + s1_s = REG_READ(ah, AR_ISR_S1_S); + } else { + s0_s = REG_READ(ah, AR_ISR_S0); + REG_WRITE(ah, AR_ISR_S0, s0_s); + s1_s = REG_READ(ah, AR_ISR_S1); + REG_WRITE(ah, AR_ISR_S1, s1_s); + + isr &= ~(AR_ISR_TXOK | + AR_ISR_TXDESC | + AR_ISR_TXERR | + AR_ISR_TXEOL); + } + ah->intr_txqs |= MS(s0_s, AR_ISR_S0_QCU_TXOK); ah->intr_txqs |= MS(s0_s, AR_ISR_S0_QCU_TXDESC); - - s1_s = REG_READ(ah, AR_ISR_S1_S); ah->intr_txqs |= MS(s1_s, AR_ISR_S1_QCU_TXERR); ah->intr_txqs |= MS(s1_s, AR_ISR_S1_QCU_TXEOL); } @@ -114,13 +133,15 @@ static bool ar9002_hw_get_isr(struct ath *masked |= mask2; } - if (AR_SREV_9100(ah)) - return true; - - if (isr & AR_ISR_GENTMR) { + if (!AR_SREV_9100(ah) && (isr & AR_ISR_GENTMR)) { u32 s5_s; - s5_s = REG_READ(ah, AR_ISR_S5_S); + if (pCap->hw_caps & ATH9K_HW_CAP_RAC_SUPPORTED) { + s5_s = REG_READ(ah, AR_ISR_S5_S); + } else { + s5_s = REG_READ(ah, AR_ISR_S5); + } + ah->intr_gen_timer_trigger = MS(s5_s, AR_ISR_S5_GENTIMER_TRIG); @@ -133,8 +154,21 @@ static bool ar9002_hw_get_isr(struct ath if ((s5_s & AR_ISR_S5_TIM_TIMER) && !(pCap->hw_caps & ATH9K_HW_CAP_AUTOSLEEP)) *masked |= ATH9K_INT_TIM_TIMER; + + if (!(pCap->hw_caps & ATH9K_HW_CAP_RAC_SUPPORTED)) { + REG_WRITE(ah, AR_ISR_S5, s5_s); + isr &= ~AR_ISR_GENTMR; + } + } + + if (!(pCap->hw_caps & ATH9K_HW_CAP_RAC_SUPPORTED)) { + REG_WRITE(ah, AR_ISR, isr); + REG_READ(ah, AR_ISR); } + if (AR_SREV_9100(ah)) + return true; + if (sync_cause) { fatal_int = (sync_cause &