From patchwork Wed Aug 29 21:32:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Cercueil X-Patchwork-Id: 10580955 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B8DB2139B for ; Wed, 29 Aug 2018 21:33:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A8FA42BB6C for ; Wed, 29 Aug 2018 21:33:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9D1AA2BB6B; Wed, 29 Aug 2018 21:33:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 42BBF2BB6B for ; Wed, 29 Aug 2018 21:33:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727535AbeH3BcJ (ORCPT ); Wed, 29 Aug 2018 21:32:09 -0400 Received: from outils.crapouillou.net ([89.234.176.41]:55478 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727267AbeH3BcI (ORCPT ); Wed, 29 Aug 2018 21:32:08 -0400 From: Paul Cercueil To: Vinod Koul , Ralf Baechle , Paul Burton Cc: od@zcrc.me, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, Daniel Silsby , Paul Cercueil Subject: [PATCH v5 14/18] dmaengine: dma-jz4780: Further residue status fix Date: Wed, 29 Aug 2018 23:32:56 +0200 Message-Id: <20180829213300.22829-15-paul@crapouillou.net> In-Reply-To: <20180829213300.22829-1-paul@crapouillou.net> References: <20180829213300.22829-1-paul@crapouillou.net> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1535578399; bh=DlDnbpEDKjFmeiXU/E5155BZtoBzBOLXoOhxAu0xxIY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=wOVcYoIauOs39k6KCN4TYJGyWZinvJkH6LvT0vQlMztSaR6+sYg9kOtMXK4Zo/TgC4KYbRZ3y6DJfGWYkFStdBoYvoxNZXk7qpmkbqRP/b1AmwklqHUO8E1vzVWnaFahZcaDknhDgpQWa/wS3SrInWpvi2Rl4I+phzHD+/DEbdQ= Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Daniel Silsby Func jz4780_dma_desc_residue() expects the index to the next hw descriptor as its last parameter. Caller func jz4780_dma_tx_status(), however, applied modulus before passing it. When the current hw descriptor was last in the list, the index passed became zero. The resulting excess of reported residue especially caused problems with cyclic DMA transfer clients, i.e. ALSA AIC audio output, which rely on this for determining current DMA location within buffer. Combined with the recent and related residue-reporting fixes, spurious ALSA audio underruns on jz4770 hardware are now fixed. Signed-off-by: Daniel Silsby Signed-off-by: Paul Cercueil Tested-by: Mathieu Malaterre --- Notes: v2: No change v3: No change v4: Add my Signed-off-by v5: No change drivers/dma/dma-jz4780.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c index d3b915ec8a09..b73d96166637 100644 --- a/drivers/dma/dma-jz4780.c +++ b/drivers/dma/dma-jz4780.c @@ -653,7 +653,7 @@ static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan, to_jz4780_dma_desc(vdesc), 0); } else if (cookie == jzchan->desc->vdesc.tx.cookie) { txstate->residue = jz4780_dma_desc_residue(jzchan, jzchan->desc, - (jzchan->curr_hwdesc + 1) % jzchan->desc->count); + jzchan->curr_hwdesc + 1); } else txstate->residue = 0;