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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,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_GIT 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 40BFAC33C9E for ; Wed, 8 Jan 2020 08:07:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17827206DA for ; Wed, 8 Jan 2020 08:07:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="x68cq71G" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727146AbgAHIHv (ORCPT ); Wed, 8 Jan 2020 03:07:51 -0500 Received: from fllv0015.ext.ti.com ([198.47.19.141]:36582 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726593AbgAHIHv (ORCPT ); Wed, 8 Jan 2020 03:07:51 -0500 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 00887X51031711; Wed, 8 Jan 2020 02:07:33 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1578470854; bh=0LePNPhQjsmvdB/jZvsH1FkQ9eB2wIq3NeRdkh9stOI=; h=From:To:CC:Subject:Date; b=x68cq71G1ZrJDnEb6xr6XEElxXdouhAOMrrfbhF4udA+QkkBpxSv2IEdh/b5sjQpv coZyuJeDPGrfLlfSnRNA3gD8Xs6tlHtCTZ5IXtX+aZvJK7aDFxmnj3xFlAtslKKejw GAFA9uHtuAhSKkA11/VI0Y5YJ3KFKu+z0UEWW9ss= Received: from DFLE106.ent.ti.com (dfle106.ent.ti.com [10.64.6.27]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id 00887XRG002530; Wed, 8 Jan 2020 02:07:33 -0600 Received: from DFLE100.ent.ti.com (10.64.6.21) by DFLE106.ent.ti.com (10.64.6.27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Wed, 8 Jan 2020 02:07:33 -0600 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE100.ent.ti.com (10.64.6.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Wed, 8 Jan 2020 02:07:33 -0600 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 00887UcT009067; Wed, 8 Jan 2020 02:07:31 -0600 From: Peter Ujfalusi To: , , , CC: , , , , Subject: [PATCH v3] iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel() Date: Wed, 8 Jan 2020 10:08:01 +0200 Message-ID: <20200108080801.14144-1-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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, -- Peter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki