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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 72D24C33CA4 for ; Sat, 11 Jan 2020 11:00:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FE0F20866 for ; Sat, 11 Jan 2020 11:00:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578740448; bh=mLQHghOqDmybltd0XVnN5VdKnRcVz0LjzKPlp43ewtU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=bYoM7wFenSFItwo9NRZZrSaiiKllubRjyXuKRoh+1Z5tkl0x7IUlqr3eANbkPBeSX FHOrMeVG7NatPywWyDhz4abO+YkGvj2O0d/QL2Vx5DHbm9w60yQlKSz1ZQIPNyZdEA 5BGplXAuE6riJmj2LxwEy1B3oz/z9KPmBz3H5dKo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729348AbgAKLAr (ORCPT ); Sat, 11 Jan 2020 06:00:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:54932 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728881AbgAKLAq (ORCPT ); Sat, 11 Jan 2020 06:00:46 -0500 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 9BA5320842; Sat, 11 Jan 2020 11:00:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578740446; bh=mLQHghOqDmybltd0XVnN5VdKnRcVz0LjzKPlp43ewtU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LGIRy8afxTZ44EuAq8HAqfOARlroZZCVwY6bUEIVAssSPbiWpP/2ZctOPGd35WrG7 QDABfptlkZ67NVhjvN40OD7dHlE5XP02HtY7/w5dR8wkeCWinSzfwYIfQerv5bnI6Q O6fv3eN1fQ/Xj5S91D0NNZ2n6DjnMFZZXac1Dt3M= Date: Sat, 11 Jan 2020 11:00:39 +0000 From: Jonathan Cameron To: Peter Ujfalusi Cc: , , , , , , , Subject: Re: [PATCH v3] iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel() Message-ID: <20200111110039.09c6b9dd@archlinux> In-Reply-To: <20200108080801.14144-1-peter.ujfalusi@ti.com> References: <20200108080801.14144-1-peter.ujfalusi@ti.com> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 8 Jan 2020 10:08:01 +0200 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 > Acked-by: Fabrice Gasnier Applied to the togreg branch of iio.git and pushed out as testing. thanks, Jonathan > --- > Hi, > > Changes since v2: > - Replace the comment as suggested by Fabrice > > Changes since v1: > - Fall back to IRQ mode only in case of ENODEV > > Regards, > Peter > > drivers/iio/adc/stm32-adc.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > index 3b291d72701c..a8d2414ee2eb 100644 > --- a/drivers/iio/adc/stm32-adc.c > +++ b/drivers/iio/adc/stm32-adc.c > @@ -1746,9 +1746,21 @@ static int stm32_adc_dma_request(struct iio_dev *indio_dev) > struct dma_slave_config config; > int ret; > > - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); > - if (!adc->dma_chan) > + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); > + if (IS_ERR(adc->dma_chan)) { > + ret = PTR_ERR(adc->dma_chan); > + if (ret != -ENODEV) { > + if (ret != -EPROBE_DEFER) > + dev_err(&indio_dev->dev, > + "DMA channel request failed with %d\n", > + ret); > + return ret; > + } > + > + /* DMA is optional: fall back to IRQ mode */ > + adc->dma_chan = NULL; > return 0; > + } > > adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, > STM32_DMA_BUFFER_SIZE,