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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1005EC33C8C for ; Tue, 7 Jan 2020 17:05:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2485208C4 for ; Tue, 7 Jan 2020 17:05:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="GrBVEeA5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728407AbgAGRFL (ORCPT ); Tue, 7 Jan 2020 12:05:11 -0500 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:49754 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728236AbgAGRFK (ORCPT ); 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Tue, 07 Jan 2020 18:04:54 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id BA55B10002A; Tue, 7 Jan 2020 18:04:53 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag5node3.st.com [10.75.127.15]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id A8EAD21F704; Tue, 7 Jan 2020 18:04:53 +0100 (CET) Received: from [10.48.0.71] (10.75.127.44) by SFHDAG5NODE3.st.com (10.75.127.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 7 Jan 2020 18:04:53 +0100 Subject: Re: [PATCH v2] mfd: stm32-timers: Use dma_request_chan() instead dma_request_slave_channel() To: Peter Ujfalusi , , , CC: , , , References: <20200107105959.18920-1-peter.ujfalusi@ti.com> From: Fabrice Gasnier Message-ID: Date: Tue, 7 Jan 2020 18:04:52 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200107105959.18920-1-peter.ujfalusi@ti.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.44] X-ClientProxiedBy: SFHDAG1NODE3.st.com (10.75.127.3) To SFHDAG5NODE3.st.com (10.75.127.15) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-01-07_05:2020-01-07,2020-01-07 signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/7/20 11:59 AM, Peter Ujfalusi wrote: > dma_request_slave_channel() is a wrapper on top of dma_request_chan() > eating up the error code. > > By using dma_request_chan() directly the driver can support deferred > probing against DMA. > > Signed-off-by: Peter Ujfalusi > --- > Hi, > > Changes since v1: > - Fall back to PIO mode only in case of ENODEV and report all other errors > > Regards, > Peter Hi Peter, Thanks for the patch, Acked-by: Fabrice Gasnier Best Regards, Fabrice > > drivers/mfd/stm32-timers.c | 32 +++++++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 9 deletions(-) > > diff --git a/drivers/mfd/stm32-timers.c b/drivers/mfd/stm32-timers.c > index efcd4b980c94..add603359124 100644 > --- a/drivers/mfd/stm32-timers.c > +++ b/drivers/mfd/stm32-timers.c > @@ -167,10 +167,11 @@ static void stm32_timers_get_arr_size(struct stm32_timers *ddata) > regmap_write(ddata->regmap, TIM_ARR, 0x0); > } > > -static void stm32_timers_dma_probe(struct device *dev, > +static int stm32_timers_dma_probe(struct device *dev, > struct stm32_timers *ddata) > { > int i; > + int ret = 0; > char name[4]; > > init_completion(&ddata->dma.completion); > @@ -179,14 +180,23 @@ static void stm32_timers_dma_probe(struct device *dev, > /* Optional DMA support: get valid DMA channel(s) or NULL */ > for (i = STM32_TIMERS_DMA_CH1; i <= STM32_TIMERS_DMA_CH4; i++) { > snprintf(name, ARRAY_SIZE(name), "ch%1d", i + 1); > - ddata->dma.chans[i] = dma_request_slave_channel(dev, name); > + ddata->dma.chans[i] = dma_request_chan(dev, name); > } > - ddata->dma.chans[STM32_TIMERS_DMA_UP] = > - dma_request_slave_channel(dev, "up"); > - ddata->dma.chans[STM32_TIMERS_DMA_TRIG] = > - dma_request_slave_channel(dev, "trig"); > - ddata->dma.chans[STM32_TIMERS_DMA_COM] = > - dma_request_slave_channel(dev, "com"); > + ddata->dma.chans[STM32_TIMERS_DMA_UP] = dma_request_chan(dev, "up"); > + ddata->dma.chans[STM32_TIMERS_DMA_TRIG] = dma_request_chan(dev, "trig"); > + ddata->dma.chans[STM32_TIMERS_DMA_COM] = dma_request_chan(dev, "com"); > + > + for (i = STM32_TIMERS_DMA_CH1; i < STM32_TIMERS_MAX_DMAS; i++) { > + if (IS_ERR(ddata->dma.chans[i])) { > + /* Save the first error code to return */ > + if (PTR_ERR(ddata->dma.chans[i]) != -ENODEV && !ret) > + ret = PTR_ERR(ddata->dma.chans[i]); > + > + ddata->dma.chans[i] = NULL; > + } > + } > + > + return ret; > } > > static void stm32_timers_dma_remove(struct device *dev, > @@ -230,7 +240,11 @@ static int stm32_timers_probe(struct platform_device *pdev) > > stm32_timers_get_arr_size(ddata); > > - stm32_timers_dma_probe(dev, ddata); > + ret = stm32_timers_dma_probe(dev, ddata); > + if (ret) { > + stm32_timers_dma_remove(dev, ddata); > + return ret; > + } > > platform_set_drvdata(pdev, ddata); > >