Return-path: Received: from s72.web-hosting.com ([198.187.29.21]:54412 "EHLO s72.web-hosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753827Ab3LNOQ2 (ORCPT ); Sat, 14 Dec 2013 09:16:28 -0500 From: Sujith Manoharan To: John Linville Cc: linux-wireless@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] ath9k: Fix interrupt handling for the AR9002 family Date: Sat, 14 Dec 2013 19:41:33 +0530 Message-Id: <1387030293-7928-1-git-send-email-sujith@msujith.org> (sfid-20131214_151631_863065_D9D11630) Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Sujith Manoharan 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: stable@vger.kernel.org Signed-off-by: Sujith Manoharan --- drivers/net/wireless/ath/ath9k/ar9002_mac.c | 44 +++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/ar9002_mac.c b/drivers/net/wireless/ath/ath9k/ar9002_mac.c index 8d78253..0337de7 100644 --- 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_hw *ah, enum ath9k_int *masked) 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_hw *ah, enum ath9k_int *masked) *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); } @@ -120,7 +139,12 @@ static bool ar9002_hw_get_isr(struct ath_hw *ah, enum ath9k_int *masked) if (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); @@ -133,6 +157,16 @@ static bool ar9002_hw_get_isr(struct ath_hw *ah, enum ath9k_int *masked) 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 (sync_cause) { -- 1.8.5.1