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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88558C433F5 for ; Thu, 10 Mar 2022 17:29:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244939AbiCJRai (ORCPT ); Thu, 10 Mar 2022 12:30:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244759AbiCJRag (ORCPT ); Thu, 10 Mar 2022 12:30:36 -0500 Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D6CBD31FB; Thu, 10 Mar 2022 09:29:35 -0800 (PST) Received: by mail-lf1-x130.google.com with SMTP id z11so10590586lfh.13; Thu, 10 Mar 2022 09:29:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=eCcJQMSaPqi5zt8beLRmZW0zLGixAnNgDgtiWNv73Rs=; b=ISQq8THvz/51DUMhVJ3UFf3Ho63QuDN/kRcpTlugmvqKPEbqM1q/rMng0POdpiQH7+ eHWgM0UgfucUKetTOrVEjA4VheUOp3CwSu03WI1z3e8VRMUeORi80qXAHEAxWWo3HNeg oF2QPEr3K7f9otkKTOMhHdq3ESlicBx3CDQorgMikF3dnWIbKsqQZ4VQLZ/gTJZNA9eO nxovBAXQ5JYSh7J1FsmL9uaPNdImv4jRpIxeRbVo/Bg03xFdEvG1+CThPYrdgTMv+zFB 5aSa/F+djggaJR6GXqBnWuttYazanYuB1UYfNfiN4oqivTQ1sUSJ/rqXOU4+dci7cmxi ZKug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=eCcJQMSaPqi5zt8beLRmZW0zLGixAnNgDgtiWNv73Rs=; b=VMWQwQVxQslP39x/WQgOgwbu/cQ0T4cQ4hHto1fox+Rwnv+ww+7h3HesyeibyHnwOQ pUtnsXIE6He4ijeugIDJ2RkOO4hijvlTRb89WWAtIX7OAp9RsjWqSEhIe+GTsQlZ5AtT u/84s2EjMtZUH+KUj+GdcckyLk1YVWbNdWJOEBhKaQsV0jJhEH9GLO4bXDus08xzWv5F JYa+MBM3gAfEBltt3C6YKccOViKbPJWVR7zp/TpGRxl+kZzzqYY6kUD6v2wMFZZlEOwp bfaBcj+2SUI3FLcqXa859ISf0OOuQArjoTt9J7k7hnK/la1/7og+bBpdTPx/pw11R17U GhDA== X-Gm-Message-State: AOAM532y68NcI6Z8LdujEptwOj39OC6NBpV14tL40lh4OdvfvA3wPffI pttXesLPj+juP87uZ3U5MHcm1pG2Bir0uw== X-Google-Smtp-Source: ABdhPJy1JXlSLyEoN59U7UXV5OXbjbLlUYc1uwaDWO3g8d3m7WcrHEIflElLRjuyqx08dJxQSxDuYQ== X-Received: by 2002:ac2:4c52:0:b0:448:27b1:8668 with SMTP id o18-20020ac24c52000000b0044827b18668mr3642876lfk.308.1646933373961; Thu, 10 Mar 2022 09:29:33 -0800 (PST) Received: from mobilestation ([95.79.188.22]) by smtp.gmail.com with ESMTPSA id f8-20020a2eb5a8000000b00247eb1b937csm1181649ljn.127.2022.03.10.09.29.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Mar 2022 09:29:33 -0800 (PST) Date: Thu, 10 Mar 2022 20:29:30 +0300 From: Serge Semin To: Frank Li Cc: Serge Semin , gustavo.pimentel@synopsys.com, hongxing.zhu@nxp.com, l.stach@pengutronix.de, linux-imx@nxp.com, linux-pci@vger.kernel.org, dmaengine@vger.kernel.org, lznuaa@gmail.com, vkoul@kernel.org, lorenzo.pieralisi@arm.com, robh@kernel.org, kw@linux.com, bhelgaas@google.com, shawnguo@kernel.org, manivannan.sadhasivam@linaro.org Subject: Re: [PATCH v4 6/8] dmaengine: dw-edma: Don't rely on the deprecated "direction" member Message-ID: <20220310172930.g7xq3txjkbwtdmbw@mobilestation> References: <20220309211204.26050-1-Frank.Li@nxp.com> <20220309211204.26050-7-Frank.Li@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220309211204.26050-7-Frank.Li@nxp.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Mar 09, 2022 at 03:12:02PM -0600, Frank Li wrote: > From: Manivannan Sadhasivam > > The "direction" member of the "dma_slave_config" structure is deprecated. > The clients no longer use this field to specify the direction of the slave > channel. But in the eDMA core, this field is used to differentiate between the > Root complex (remote) and Endpoint (local) DMA accesses. > > Nevertheless, we can't differentiate between local and remote accesses without > a dedicated flag. So let's get rid of the old check and add a new check for > verifying the DMA operation between local and remote memory instead. > > Signed-off-by: Manivannan Sadhasivam > Signed-off-by: Frank Li > --- > no chang between v1 to v4 > drivers/dma/dw-edma/dw-edma-core.c | 17 ++--------------- > 1 file changed, 2 insertions(+), 15 deletions(-) > > diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c > index 507f08db1aad3..47c6a52929fcd 100644 > --- a/drivers/dma/dw-edma/dw-edma-core.c > +++ b/drivers/dma/dw-edma/dw-edma-core.c > @@ -341,22 +341,9 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer) > if (!chan->configured) > return NULL; > > - switch (chan->config.direction) { > - case DMA_DEV_TO_MEM: /* local DMA */ > - if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ) > - break; > - return NULL; > - case DMA_MEM_TO_DEV: /* local DMA */ > - if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE) > - break; > + /* eDMA supports only read and write between local and remote memory */ The comment is a bit confusing because both cases are named as "memory" while the permitted directions contains DEV-part, which means "device". What I would suggest to write here is something like: "DW eDMA supports transferring data from/to the CPU/Application memory to/from the PCIe link partner device by injecting the PCIe MWr/MRd TLPs." -Sergey > + if (dir != DMA_DEV_TO_MEM && dir != DMA_MEM_TO_DEV) > return NULL; > - default: /* remote DMA */ > - if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_READ) > - break; > - if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_WRITE) > - break; > - return NULL; > - } > > if (xfer->type == EDMA_XFER_CYCLIC) { > if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt) > -- > 2.24.0.rc1 >