From patchwork Thu Apr 17 14:40:44 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 4009131 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 [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 1C5FABFF02 for ; Thu, 17 Apr 2014 14:43:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 548D620394 for ; Thu, 17 Apr 2014 14:43:24 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7FC972038E for ; Thu, 17 Apr 2014 14:43:23 +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 1WanUx-0004Ou-Vs; Thu, 17 Apr 2014 14:41:07 +0000 Received: from galois.linutronix.de ([2001:470:1f0b:db:abcd:42:0:1]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WanUi-0004I9-CE for linux-arm-kernel@lists.infradead.org; Thu, 17 Apr 2014 14:40:54 +0000 Received: from localhost ([127.0.0.1] helo=ionos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1WanUM-0004k1-9J; Thu, 17 Apr 2014 16:40:30 +0200 Message-Id: <20140417143249.273350892@linutronix.de> User-Agent: quilt/0.60-1 Date: Thu, 17 Apr 2014 14:40:44 -0000 From: Thomas Gleixner To: dmaengine@vger.kernel.org Subject: [patch 2/6] dma: edma: Check the current decriptor first in tx_status() References: <20140417133737.892475126@linutronix.de> Content-Disposition: inline; filename=dma-edma-tx-status-check-current-desc-first.patch X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140417_074052_581217_E54277A5 X-CRM114-Status: UNSURE ( 6.30 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.7 (/) Cc: vinod.koul@intel.com, nsekhar@ti.com, Peter Ujfalusi , joelf@ti.com, dan.j.williams@intel.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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 It's likely that the caller investigates the status of a currently active descriptor. Make that simple check first and only rumage in the vchan list if that fails. Signed-off-by: Thomas Gleixner --- drivers/dma/edma.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) Index: linux-2.6/drivers/dma/edma.c =================================================================== --- linux-2.6.orig/drivers/dma/edma.c +++ linux-2.6/drivers/dma/edma.c @@ -774,11 +774,10 @@ static enum dma_status edma_tx_status(st return ret; spin_lock_irqsave(&echan->vchan.lock, flags); - vdesc = vchan_find_desc(&echan->vchan, cookie); - if (vdesc) - txstate->residue = to_edma_desc(&vdesc->tx)->residue; - else if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) + if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) txstate->residue = echan->edesc->residue; + else if ((vdesc = vchan_find_desc(&echan->vchan, cookie))) + txstate->residue = to_edma_desc(&vdesc->tx)->residue; spin_unlock_irqrestore(&echan->vchan.lock, flags); return ret;