From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C0341C31E51 for ; Tue, 18 Jun 2019 04:56:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F35E20B1F for ; Tue, 18 Jun 2019 04:56:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560833782; bh=p/1WgzjyDGLLUL8w56446SHwaaWDO2rQKvXQxt/cSOE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=qStcLfT3efgg5WHrXMipRpksSyZpYOpXxXG1uoKeJm5Wv9m9PHDQSBpzvPJVmWKo0 4fJKH5cIi9QX1pqxdNhf/xlsbcy6V93k7yTjC2qeiYTDD2HuDbOzdNPjZ9PAbPfBtV RVwoav1d1KquaH728RE+ilVjB9kcgDHceHV/PP1k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726428AbfFRE4W (ORCPT ); Tue, 18 Jun 2019 00:56:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:46392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725900AbfFRE4V (ORCPT ); Tue, 18 Jun 2019 00:56:21 -0400 Received: from localhost (unknown [122.178.226.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 639A12085A; Tue, 18 Jun 2019 04:56:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560833781; bh=p/1WgzjyDGLLUL8w56446SHwaaWDO2rQKvXQxt/cSOE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mLARzcNdUkEGgZ6QGRCy1f8/hT1C52+XCSQoCJtQofiim3IBDE61VXQboKn7OSnQB kl9r5cEauFP3BdsUQkFjXA9tz42XRh9QCI6hydwe+7mFnSxAy39pQskRuJfSc+Eo9X tHV3NswGQd/50ocwL2XpOHmRGf5i66vfC7zJt4LE= Date: Tue, 18 Jun 2019 10:23:12 +0530 From: Vinod Koul To: Srinivas Kandagatla Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, sricharan@codeaurora.org Subject: Re: [PATCH] dmaengine: qcom-bam: fix circular buffer handling Message-ID: <20190618045312.GK2962@vkoul-mobl> References: <20190614142012.31384-1-srinivas.kandagatla@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190614142012.31384-1-srinivas.kandagatla@linaro.org> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 14-06-19, 15:20, Srinivas Kandagatla wrote: > For some reason arguments to most of the circular buffers > macros are used in reverse, tail is used for head and vice versa. > > This leads to bam thinking that there is an extra descriptor at the > end and leading to retransmitting descriptor which was not scheduled > by any driver. This happens after MAX_DESCRIPTORS (4096) are scheduled > and done, so most of the drivers would not notice this, unless they are > heavily using bam dma. Originally found this issue while testing > SoundWire over SlimBus on DB845c which uses DMA very heavily for > read/writes. Applied and copied stable, thanks -- ~Vinod