From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2E76C77B7F for ; Mon, 8 May 2023 11:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236278AbjEHLnl (ORCPT ); Mon, 8 May 2023 07:43:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236257AbjEHLnX (ORCPT ); Mon, 8 May 2023 07:43:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DF7772BE for ; Mon, 8 May 2023 04:42:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 996A9635BE for ; Mon, 8 May 2023 11:41:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 903A8C433AA; Mon, 8 May 2023 11:41:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683546112; bh=oTlM6QwoHU60c8Rk06LcMqRQgGGh7eAg8gv0p/Gudpo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bf8atGGsSM7bUYauLdtIEHyxRdIVdDhQDaZF/Jg6YPLTQlvBV0DVy/urwnu6fUorw 62yZeoQWnhhBB7pfVSuyOr3of9IQcrRetS9zEB4Z1fTBBua+71sIbYZYhGy8TJNM0i NK9JhSDRQskKmkx0HiWTou6gz7OsNyD5IPdS9VVk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Wang , Deren Wu , Wang Zhao , Quan Zhou , Felix Fietkau , Sasha Levin Subject: [PATCH 5.15 221/371] wifi: mt76: mt7921e: improve reliability of dma reset Date: Mon, 8 May 2023 11:47:02 +0200 Message-Id: <20230508094820.837459683@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094811.912279944@linuxfoundation.org> References: <20230508094811.912279944@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Quan Zhou [ Upstream commit 87714bf6ed1589813e473db5471e6e9857755764 ] The hardware team has advised the driver that it is necessary to first put WFDMA into an idle state before resetting the WFDMA. Otherwise, the WFDMA may enter an unknown state where it cannot be polled with the right state successfully. To ensure that the DMA can work properly while a stressful cold reboot test was being made, we have reordered the programming sequence in the driver based on the hardware team's guidance. The patch would modify the WFDMA disabling flow from "DMA reset -> disabling DMASHDL -> disabling WFDMA -> polling and waiting until DMA idle" to "disabling WFDMA -> polling and waiting for DMA idle -> disabling DMASHDL -> DMA reset. Where he polling and waiting until WFDMA is idle is coordinated with the operation of disabling WFDMA. Even while WFDMA is being disabled, it can still handle Tx/Rx requests. The additional polling allows sufficient time for WFDMA to process the last T/Rx request. When the idle state of WFDMA is reached, it is a reliable indication that DMASHDL is also idle to ensure it is safe to disable it and perform the DMA reset. Fixes: 0a1059d0f060 ("mt76: mt7921: move mt7921_dma_reset in dma.c") Co-developed-by: Sean Wang Signed-off-by: Sean Wang Co-developed-by: Deren Wu Signed-off-by: Deren Wu Co-developed-by: Wang Zhao Signed-off-by: Wang Zhao Signed-off-by: Quan Zhou Signed-off-by: Felix Fietkau Signed-off-by: Sasha Levin --- .../net/wireless/mediatek/mt76/mt7921/dma.c | 36 ++++++++++--------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/dma.c b/drivers/net/wireless/mediatek/mt76/mt7921/dma.c index 7e39bcfdb0b7a..983861edc6834 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/dma.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/dma.c @@ -120,22 +120,6 @@ static void mt7921_dma_prefetch(struct mt7921_dev *dev) static int mt7921_dma_disable(struct mt7921_dev *dev, bool force) { - if (force) { - /* reset */ - mt76_clear(dev, MT_WFDMA0_RST, - MT_WFDMA0_RST_DMASHDL_ALL_RST | - MT_WFDMA0_RST_LOGIC_RST); - - mt76_set(dev, MT_WFDMA0_RST, - MT_WFDMA0_RST_DMASHDL_ALL_RST | - MT_WFDMA0_RST_LOGIC_RST); - } - - /* disable dmashdl */ - mt76_clear(dev, MT_WFDMA0_GLO_CFG_EXT0, - MT_WFDMA0_CSR_TX_DMASHDL_ENABLE); - mt76_set(dev, MT_DMASHDL_SW_CONTROL, MT_DMASHDL_DMASHDL_BYPASS); - /* disable WFDMA0 */ mt76_clear(dev, MT_WFDMA0_GLO_CFG, MT_WFDMA0_GLO_CFG_TX_DMA_EN | MT_WFDMA0_GLO_CFG_RX_DMA_EN | @@ -149,6 +133,22 @@ static int mt7921_dma_disable(struct mt7921_dev *dev, bool force) MT_WFDMA0_GLO_CFG_RX_DMA_BUSY, 0, 100, 1)) return -ETIMEDOUT; + /* disable dmashdl */ + mt76_clear(dev, MT_WFDMA0_GLO_CFG_EXT0, + MT_WFDMA0_CSR_TX_DMASHDL_ENABLE); + mt76_set(dev, MT_DMASHDL_SW_CONTROL, MT_DMASHDL_DMASHDL_BYPASS); + + if (force) { + /* reset */ + mt76_clear(dev, MT_WFDMA0_RST, + MT_WFDMA0_RST_DMASHDL_ALL_RST | + MT_WFDMA0_RST_LOGIC_RST); + + mt76_set(dev, MT_WFDMA0_RST, + MT_WFDMA0_RST_DMASHDL_ALL_RST | + MT_WFDMA0_RST_LOGIC_RST); + } + return 0; } @@ -354,6 +354,10 @@ void mt7921_dma_cleanup(struct mt7921_dev *dev) MT_WFDMA0_GLO_CFG_OMIT_RX_INFO | MT_WFDMA0_GLO_CFG_OMIT_RX_INFO_PFET2); + mt76_poll_msec_tick(dev, MT_WFDMA0_GLO_CFG, + MT_WFDMA0_GLO_CFG_TX_DMA_BUSY | + MT_WFDMA0_GLO_CFG_RX_DMA_BUSY, 0, 100, 1); + /* reset */ mt76_clear(dev, MT_WFDMA0_RST, MT_WFDMA0_RST_DMASHDL_ALL_RST | -- 2.39.2