From nobody Mon Apr 6 11:53:07 2026 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 6CE28C07E9D for ; Mon, 26 Sep 2022 17:37:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230344AbiIZRhA (ORCPT ); Mon, 26 Sep 2022 13:37:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230519AbiIZRga (ORCPT ); Mon, 26 Sep 2022 13:36:30 -0400 Received: from hi1smtp01.de.adit-jv.com (smtp1.de.adit-jv.com [93.241.18.167]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC25D74DCA for ; Mon, 26 Sep 2022 09:58:21 -0700 (PDT) Received: from hi2exch02.adit-jv.com (hi2exch02.adit-jv.com [10.72.92.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by hi1smtp01.de.adit-jv.com (Postfix) with ESMTPS id 22BEC5202DB; Mon, 26 Sep 2022 18:58:20 +0200 (CEST) Received: from localhost.localdomain (10.72.94.2) by hi2exch02.adit-jv.com (10.72.92.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.12; Mon, 26 Sep 2022 18:58:19 +0200 From: Eugeniu Rosca To: Lars-Peter Clausen , Vinod Koul , Mark Brown , Jaroslav Kysela , Takashi Iwai , , CC: Jiada Wang , Dean Jenkins , Andreas Pape , Eugeniu Rosca , Eugeniu Rosca Subject: [PATCH] ALSA: dmaengine: increment buffer pointer atomically Date: Mon, 26 Sep 2022 18:58:13 +0200 Message-ID: <1664211493-11789-1-git-send-email-erosca@de.adit-jv.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Originating-IP: [10.72.94.2] X-ClientProxiedBy: hi2exch02.adit-jv.com (10.72.92.28) To hi2exch02.adit-jv.com (10.72.92.28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Andreas Pape Setting pointer and afterwards checking for wraparound leads to the possibility of returning the inconsistent pointer position. This patch increments buffer pointer atomically to avoid this issue. Fixes: e7f73a1613567a ("ASoC: Add dmaengine PCM helper functions") Signed-off-by: Andreas Pape Signed-off-by: Eugeniu Rosca --- sound/core/pcm_dmaengine.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c index 5b2ca028f5aa..494ec0c207fa 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -133,12 +133,14 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_d= ai_data); =20 static void dmaengine_pcm_dma_complete(void *arg) { + unsigned int new_pos; struct snd_pcm_substream *substream =3D arg; struct dmaengine_pcm_runtime_data *prtd =3D substream_to_prtd(substream); =20 - prtd->pos +=3D snd_pcm_lib_period_bytes(substream); - if (prtd->pos >=3D snd_pcm_lib_buffer_bytes(substream)) - prtd->pos =3D 0; + new_pos =3D prtd->pos + snd_pcm_lib_period_bytes(substream); + if (new_pos >=3D snd_pcm_lib_buffer_bytes(substream)) + new_pos =3D 0; + prtd->pos =3D new_pos; =20 snd_pcm_period_elapsed(substream); } --=20 2.37.2