From patchwork Fri Mar 25 09:16:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Appana Durga Kedareswara rao X-Patchwork-Id: 8669211 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 9D319C0553 for ; Fri, 25 Mar 2016 09:19:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AEAEE20351 for ; Fri, 25 Mar 2016 09:19:10 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D392220270 for ; Fri, 25 Mar 2016 09:19:09 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ajNri-00025n-Hz; Fri, 25 Mar 2016 09:17:10 +0000 Received: from mail-cys01nam02on0073.outbound.protection.outlook.com ([104.47.37.73] helo=NAM02-CY1-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ajNrf-0001oQ-Bi for linux-arm-kernel@lists.infradead.org; Fri, 25 Mar 2016 09:17:08 +0000 Received: from BL2NAM02FT004.eop-nam02.prod.protection.outlook.com (10.152.76.56) by BL2NAM02HT119.eop-nam02.prod.protection.outlook.com (10.152.76.241) with Microsoft SMTP Server (TLS) id 15.1.453.6; Fri, 25 Mar 2016 09:16:45 +0000 Authentication-Results: spf=pass (sender IP is 149.199.60.83) smtp.mailfrom=xilinx.com; vger.kernel.org; dkim=none (message not signed) header.d=none;vger.kernel.org; dmarc=bestguesspass action=none header.from=xilinx.com; Received-SPF: Pass (protection.outlook.com: domain of xilinx.com designates 149.199.60.83 as permitted sender) receiver=protection.outlook.com; client-ip=149.199.60.83; helo=xsj-pvapsmtpgw01; Received: from xsj-pvapsmtpgw01 (149.199.60.83) by BL2NAM02FT004.mail.protection.outlook.com (10.152.76.168) with Microsoft SMTP Server (TLS) id 15.1.453.6 via Frontend Transport; Fri, 25 Mar 2016 09:16:44 +0000 Received: from unknown-38-66.xilinx.com ([149.199.38.66] helo=xsj-pvapsmtp01) by xsj-pvapsmtpgw01 with esmtp (Exim 4.63) (envelope-from ) id 1ajNrI-0007mM-1u; Fri, 25 Mar 2016 02:16:44 -0700 Received: from [127.0.0.1] (helo=localhost) by xsj-pvapsmtp01 with smtp (Exim 4.63) (envelope-from ) id 1ajNrH-0006CW-Tt; Fri, 25 Mar 2016 02:16:43 -0700 Received: from xsj-pvapsmtp01 (smtp2.xilinx.com [149.199.38.66]) by xsj-smtp-dlp1.xlnx.xilinx.com (8.13.8/8.13.1) with ESMTP id u2P9GfRa010916; Fri, 25 Mar 2016 02:16:42 -0700 Received: from [172.23.64.207] (helo=xhd-lin64re117.xilinx.com) by xsj-pvapsmtp01 with esmtp (Exim 4.63) (envelope-from ) id 1ajNrF-0006Bt-Nl; Fri, 25 Mar 2016 02:16:41 -0700 Received: by xhd-lin64re117.xilinx.com (Postfix, from userid 13614) id EB19120954; Fri, 25 Mar 2016 14:46:40 +0530 (IST) From: Kedareswara rao Appana To: , , , , , , , , , Subject: [PATCH v3 2/2] dmaengine: vdma: Fix race condition in Non-SG mode Date: Fri, 25 Mar 2016 14:46:39 +0530 Message-ID: <1458897399-3939-1-git-send-email-appanad@xilinx.com> X-Mailer: git-send-email 2.1.2 X-RCIS-Action: ALLOW X-TM-AS-Product-Ver: IMSS-7.1.0.1224-8.0.0.1202-22218.003 X-TM-AS-User-Approved-Sender: Yes;Yes X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:149.199.60.83; IPV:NLI; CTRY:US; EFV:NLI; SFV:NSPM; SFS:(10009020)(6009001)(2980300002)(438002)(199003)(189002)(4001450100002)(103686003)(1096002)(5008740100001)(45336002)(189998001)(36756003)(63266004)(86362001)(87936001)(47776003)(50986999)(4326007)(1220700001)(36386004)(90966002)(42186005)(50466002)(2906002)(50226001)(2201001)(48376002)(46386002)(6806005)(5003940100001)(19580395003)(19580405001)(33646002)(52956003)(92566002)(106466001)(229853001)(81166005)(586003)(5001770100001)(921003)(107986001)(83996005)(1121003)(2101003); DIR:OUT; SFP:1101; SCL:1; SRVR:BL2NAM02HT119; H:xsj-pvapsmtpgw01; FPR:; SPF:Pass; MLV:sfv; A:1; MX:1; LANG:en; MIME-Version: 1.0 X-MS-Office365-Filtering-Correlation-Id: 5d205e4d-acca-4680-d692-08d3548e2f9b X-Microsoft-Antispam: UriScan:; BCL:0; PCL:0; RULEID:(8251501002); SRVR:BL2NAM02HT119; X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0; PCL:0; RULEID:(601004)(2401047)(8121501046)(13017025)(13018025)(13015025)(13023025)(5005006)(13024025)(3002001)(10201501046); SRVR:BL2NAM02HT119; BCL:0; PCL:0; RULEID:; SRVR:BL2NAM02HT119; X-Forefront-PRVS: 0892FA9A88 X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Mar 2016 09:16:44.7546 (UTC) X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c; Ip=[149.199.60.83]; Helo=[xsj-pvapsmtpgw01] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL2NAM02HT119 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160325_021707_577253_1D6B1998 X-CRM114-Status: GOOD ( 13.74 ) X-Spam-Score: -1.9 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When VDMA is configured in Non-sg mode Users can queue descriptors greater than h/w configured frames. Current driver allows the user to queue descriptors upto h/w configured. Which is wrong for non-sg mode configuration. This patch fixes this issue. Signed-off-by: Kedareswara rao Appana --- Changes for v3: ---> New patch. drivers/dma/xilinx/xilinx_vdma.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c index abe915c..b873d98 100644 --- a/drivers/dma/xilinx/xilinx_vdma.c +++ b/drivers/dma/xilinx/xilinx_vdma.c @@ -209,6 +209,7 @@ struct xilinx_vdma_tx_descriptor { * @flush_on_fsync: Flush on Frame sync * @desc_pendingcount: Descriptor pending count * @ext_addr: Indicates 64 bit addressing is supported by dma channel + * @desc_submitcount: Descriptor h/w submitted count */ struct xilinx_vdma_chan { struct xilinx_vdma_device *xdev; @@ -233,6 +234,7 @@ struct xilinx_vdma_chan { bool flush_on_fsync; u32 desc_pendingcount; bool ext_addr; + u32 desc_submitcount; }; /** @@ -716,9 +718,10 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) struct xilinx_vdma_tx_segment *segment, *last = NULL; int i = 0; - list_for_each_entry(desc, &chan->pending_list, node) { - segment = list_first_entry(&desc->segments, - struct xilinx_vdma_tx_segment, node); + if (chan->desc_submitcount < chan->num_frms) + i = chan->desc_submitcount; + + list_for_each_entry(segment, &desc->segments, node) { if (chan->ext_addr) vdma_desc_write_64(chan, XILINX_VDMA_REG_START_ADDRESS_64(i++), @@ -742,8 +745,17 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) vdma_desc_write(chan, XILINX_VDMA_REG_VSIZE, last->hw.vsize); } - list_splice_tail_init(&chan->pending_list, &chan->active_list); - chan->desc_pendingcount = 0; + if (!chan->has_sg) { + list_del(&desc->node); + list_add_tail(&desc->node, &chan->active_list); + chan->desc_submitcount++; + chan->desc_pendingcount--; + if (chan->desc_submitcount == chan->num_frms) + chan->desc_submitcount = 0; + } else { + list_splice_tail_init(&chan->pending_list, &chan->active_list); + chan->desc_pendingcount = 0; + } } /** @@ -927,7 +939,8 @@ append: list_add_tail(&desc->node, &chan->pending_list); chan->desc_pendingcount++; - if (unlikely(chan->desc_pendingcount > chan->num_frms)) { + if (chan->has_sg && + unlikely(chan->desc_pendingcount > chan->num_frms)) { dev_dbg(chan->dev, "desc pendingcount is too high\n"); chan->desc_pendingcount = chan->num_frms; }