Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751402AbeACTlz (ORCPT + 1 other); Wed, 3 Jan 2018 14:41:55 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:33960 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751210AbeACTlx (ORCPT ); Wed, 3 Jan 2018 14:41:53 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C6E476032D Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sboyd@codeaurora.org Date: Wed, 3 Jan 2018 11:41:51 -0800 From: Stephen Boyd To: Srinivas Kandagatla Cc: Andy Gross , Mark Brown , linux-arm-msm@vger.kernel.org, alsa-devel@alsa-project.org, David Brown , Rob Herring , Mark Rutland , Liam Girdwood , Patrick Lai , Banajit Goswami , Jaroslav Kysela , Takashi Iwai , linux-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RESEND PATCH v2 14/15] ASoC: qcom: apq8096: Add db820c machine driver Message-ID: <20180103194151.GA21040@codeaurora.org> References: <20171214173402.19074-1-srinivas.kandagatla@linaro.org> <20171214173402.19074-15-srinivas.kandagatla@linaro.org> <4db358ab-3171-bb08-ca26-ec9bf282e8d4@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4db358ab-3171-bb08-ca26-ec9bf282e8d4@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 01/03, Srinivas Kandagatla wrote: > Thanks for your review comments, > > On 03/01/18 17:20, Stephen Boyd wrote: > >>+ > >>+ return ret; > >>+} > >>+ > >>+static int msm_snd_apq8096_probe(struct platform_device *pdev) > >>+{ > >>+ int ret; > >>+ struct snd_soc_card *card; > >>+ > >>+ card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL); > >>+ if (!card) > >>+ return -ENOMEM; > >>+ > >>+ card->dev = &pdev->dev; > >>+ > >>+ ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32)); > > > >Why do we need to do this? Can you add some sort of comment in the code > >about why? > > Even though dsp supports 64 bit addresses, but the sid sits at > offset of 32, which brings this restriction of supporting only 32 > bit iova. > Doesn't the dsp have an iommu in place to make the address translation from 64 to 32 bits transparent? I thought this was what dma-ranges and iommu binding was for, but I'm not well versed on all the details here. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project