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 7C86CC4332F for ; Sat, 18 Dec 2021 09:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232630AbhLRJ6H (ORCPT ); Sat, 18 Dec 2021 04:58:07 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:39440 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S232559AbhLRJ6B (ORCPT ); Sat, 18 Dec 2021 04:58:01 -0500 X-UUID: 0c2b7710c3f2485f8ce2029edcb8fdff-20211218 X-UUID: 0c2b7710c3f2485f8ce2029edcb8fdff-20211218 Received: from mtkexhb02.mediatek.inc [(172.21.101.103)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 586415106; Sat, 18 Dec 2021 17:57:58 +0800 Received: from mtkexhb02.mediatek.inc (172.21.101.103) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.15; Sat, 18 Dec 2021 17:57:57 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) by mtkexhb02.mediatek.inc (172.21.101.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 18 Dec 2021 17:57:57 +0800 Received: from mhfsdcap04.gcn.mediatek.inc (10.17.3.154) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 18 Dec 2021 17:57:56 +0800 From: Chunfeng Yun To: Greg Kroah-Hartman CC: Chunfeng Yun , Matthias Brugger , Felipe Balbi , , , , , "Eddie Hung" , Subject: [PATCH v2 2/4] usb: mtu3: add memory barrier before set GPD's HWO Date: Sat, 18 Dec 2021 17:57:47 +0800 Message-ID: <20211218095749.6250-2-chunfeng.yun@mediatek.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211218095749.6250-1-chunfeng.yun@mediatek.com> References: <20211218095749.6250-1-chunfeng.yun@mediatek.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a seldom issue that the controller access invalid address and trigger devapc or emimpu violation. That is due to memory access is out of order and cause gpd data is not correct. Add mb() to prohibit compiler or cpu from reordering to make sure GPD is fully written before setting its HWO. Fixes: 48e0d3735aa5 ("usb: mtu3: supports new QMU format") Cc: stable@vger.kernel.org Reported-by: Eddie Hung Signed-off-by: Chunfeng Yun --- v2: modify misleading comment and commit message --- drivers/usb/mtu3/mtu3_qmu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c index 3f414f91b589..2ea3157ddb6e 100644 --- a/drivers/usb/mtu3/mtu3_qmu.c +++ b/drivers/usb/mtu3/mtu3_qmu.c @@ -273,6 +273,8 @@ static int mtu3_prepare_tx_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq) gpd->dw3_info |= cpu_to_le32(GPD_EXT_FLAG_ZLP); } + /* prevent reorder, make sure GPD's HWO is set last */ + mb(); gpd->dw0_info |= cpu_to_le32(GPD_FLAGS_IOC | GPD_FLAGS_HWO); mreq->gpd = gpd; @@ -306,6 +308,8 @@ static int mtu3_prepare_rx_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq) gpd->next_gpd = cpu_to_le32(lower_32_bits(enq_dma)); ext_addr |= GPD_EXT_NGP(mtu, upper_32_bits(enq_dma)); gpd->dw3_info = cpu_to_le32(ext_addr); + /* prevent reorder, make sure GPD's HWO is set last */ + mb(); gpd->dw0_info |= cpu_to_le32(GPD_FLAGS_IOC | GPD_FLAGS_HWO); mreq->gpd = gpd; @@ -445,7 +449,8 @@ static void qmu_tx_zlp_error_handler(struct mtu3 *mtu, u8 epnum) return; } mtu3_setbits(mbase, MU3D_EP_TXCR0(mep->epnum), TX_TXPKTRDY); - + /* prevent reorder, make sure GPD's HWO is set last */ + mb(); /* by pass the current GDP */ gpd_current->dw0_info |= cpu_to_le32(GPD_FLAGS_BPS | GPD_FLAGS_HWO); -- 2.18.0