Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754093AbdGXN40 (ORCPT ); Mon, 24 Jul 2017 09:56:26 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:36339 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753352AbdGXN4R (ORCPT ); Mon, 24 Jul 2017 09:56:17 -0400 From: Pierre Yves MORDRET To: Vinod Koul CC: Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre TORGUE , Russell King , Dan Williams , "M'boumba Cedric Madianga" , Fabrice GASNIER , Herbert Xu , Fabien DESSENNE , Amelie DELAUNAY , "dmaengine@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3 2/5] dmaengine: Add STM32 DMAMUX driver Thread-Topic: [PATCH v3 2/5] dmaengine: Add STM32 DMAMUX driver Thread-Index: AQHS9lJEsWaINqWfUEGtL1SBd5FJmqJfX72AgAObA4A= Date: Mon, 24 Jul 2017 13:55:10 +0000 Message-ID: <2b916330-9b65-f4d5-817f-79b66cc236b3@st.com> References: <1499343623-5964-1-git-send-email-pierre-yves.mordret@st.com> <1499343623-5964-3-git-send-email-pierre-yves.mordret@st.com> <20170722065133.GT3053@localhost> In-Reply-To: <20170722065133.GT3053@localhost> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.46] Content-Type: text/plain; charset="utf-8" Content-ID: <0F4A7EFD5F59A942A5E361513F54461D@st.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-24_10:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v6ODuW9a010940 Content-Length: 2523 Lines: 89 On 07/22/2017 08:51 AM, Vinod Koul wrote: > On Thu, Jul 06, 2017 at 02:20:20PM +0200, Pierre-Yves MORDRET wrote: >> +static int stm32_dmamux_probe(struct platform_device *pdev) >> +{ >> + struct device_node *node = pdev->dev.of_node; >> + struct device_node *dma_node; >> + struct stm32_dmamux_data *stm32_dmamux; >> + struct resource *res; >> + void __iomem *iomem; >> + int i, ret; >> + >> + if (!node) >> + return -ENODEV; >> + >> + stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux), >> + GFP_KERNEL); >> + if (!stm32_dmamux) >> + return -ENOMEM; >> + >> + dma_node = of_parse_phandle(node, "dma-masters", 0); >> + if (!dma_node) { >> + dev_err(&pdev->dev, "Can't get DMA master node\n"); >> + return -ENODEV; >> + } >> + >> + if (device_property_read_u32(&pdev->dev, "dma-channels", >> + &stm32_dmamux->dmamux_channels)) >> + stm32_dmamux->dmamux_channels = STM32_DMAMUX_MAX_CHANNELS; >> + >> + if (device_property_read_u32(&pdev->dev, "dma-requests", >> + &stm32_dmamux->dmamux_requests)) >> + stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS; > > I think defaults should be warned here too > ok >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + if (!res) >> + return -ENODEV; >> + >> + iomem = devm_ioremap_resource(&pdev->dev, res); >> + if (!iomem) >> + return -ENOMEM; >> + >> + spin_lock_init(&stm32_dmamux->lock); >> + >> + stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL); >> + if (IS_ERR(stm32_dmamux->clk)) { >> + dev_info(&pdev->dev, "Missing controller clock\n"); > > Can you check for EPROBE_DEFER and print only for if that is not the error > otherwise we end up sapmming with defered probe issues > This is what you meant ? if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER) { dev_info(&pdev->dev, "Missing controller clock\n"); return PTR_ERR(stm32_dmamux->clk); } OR if (IS_ERR(stm32_dmamux->clk)) { if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER) dev_info(&pdev->dev, "Missing controller clock\n"); return PTR_ERR(stm32_dmamux->clk); } >> + >> +#ifndef __DMA_STM32_DMAMUX_H >> +#define __DMA_STM32_DMAMUX_H >> + >> +#if defined(CONFIG_STM32_DMAMUX) >> +int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 chan_id); > > Why do we need a custom API in this case? > This API is called by DMA when a slave is requested by client. DMA can work without DMAMUX this API has been put in place to configure DMAMUX whether client is requesting a DMAMUX Channel instead of a DMA one. Thanks Py