From patchwork Tue Apr 28 18:24:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 226931 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 611C4C83007 for ; Tue, 28 Apr 2020 18:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BE8921707 for ; Tue, 28 Apr 2020 18:30:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098610; bh=YL6nTEoKaObranvHZ0CHYwaKUbCoDoNoOlaCNDWQbdw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Km7g4NVqLv9ZDO6gnnd8R9YsHbUZFx6LzC9enCFKaee0ha8KxcxSJ3GFpCYOsBS2h yCseL5PWaGVuY7QZAcJY1fgPdrh0NC1FSwOkaTbiWjMcVgtdBIUoiUD+TrD1dzJgou 2zy+w/B7KPJ9IctD2ghREvdgEMLPEhAO/sTmjmKs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729432AbgD1SaJ (ORCPT ); Tue, 28 Apr 2020 14:30:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:44536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729459AbgD1SaI (ORCPT ); Tue, 28 Apr 2020 14:30:08 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 E675720B80; Tue, 28 Apr 2020 18:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098607; bh=YL6nTEoKaObranvHZ0CHYwaKUbCoDoNoOlaCNDWQbdw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aa/wYpgB2ngZd3jKNQjl5tc9ZoC1Tn23VjGuR0Cvqf3zn2h/OPyQWx30OcQRGbF9m G9DvR4bivMCz5Rwo7C1zY7KwjRwsbdqjZrvEfDG5jxagAvkxnanWnitn08uCUhbegE sUxya1EpApC1IsRrgY1dBoU32Sr+nQcVFxOR3em0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Olivier Moysan , Fabrice Gasnier , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 5.6 084/167] iio: adc: stm32-adc: fix sleep in atomic context Date: Tue, 28 Apr 2020 20:24:20 +0200 Message-Id: <20200428182235.606738542@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182225.451225420@linuxfoundation.org> References: <20200428182225.451225420@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Olivier Moysan commit e2042d2936dfc84e9c600fe9b9d0039ca0e54b7d upstream. This commit fixes the following error: "BUG: sleeping function called from invalid context at kernel/irq/chip.c" In DMA mode suppress the trigger irq handler, and make the buffer transfers directly in DMA callback, instead. Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") Signed-off-by: Olivier Moysan Acked-by: Fabrice Gasnier Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/stm32-adc.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1418,8 +1418,30 @@ static unsigned int stm32_adc_dma_residu static void stm32_adc_dma_buffer_done(void *data) { struct iio_dev *indio_dev = data; + struct stm32_adc *adc = iio_priv(indio_dev); + int residue = stm32_adc_dma_residue(adc); + + /* + * In DMA mode the trigger services of IIO are not used + * (e.g. no call to iio_trigger_poll). + * Calling irq handler associated to the hardware trigger is not + * relevant as the conversions have already been done. Data + * transfers are performed directly in DMA callback instead. + * This implementation avoids to call trigger irq handler that + * may sleep, in an atomic context (DMA irq handler context). + */ + dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi); + + while (residue >= indio_dev->scan_bytes) { + u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi]; - iio_trigger_poll_chained(indio_dev->trig); + iio_push_to_buffers(indio_dev, buffer); + + residue -= indio_dev->scan_bytes; + adc->bufi += indio_dev->scan_bytes; + if (adc->bufi >= adc->rx_buf_sz) + adc->bufi = 0; + } } static int stm32_adc_dma_start(struct iio_dev *indio_dev) @@ -1845,6 +1867,7 @@ static int stm32_adc_probe(struct platfo { struct iio_dev *indio_dev; struct device *dev = &pdev->dev; + irqreturn_t (*handler)(int irq, void *p) = NULL; struct stm32_adc *adc; int ret; @@ -1911,9 +1934,11 @@ static int stm32_adc_probe(struct platfo if (ret < 0) return ret; + if (!adc->dma_chan) + handler = &stm32_adc_trigger_handler; + ret = iio_triggered_buffer_setup(indio_dev, - &iio_pollfunc_store_time, - &stm32_adc_trigger_handler, + &iio_pollfunc_store_time, handler, &stm32_adc_buffer_setup_ops); if (ret) { dev_err(&pdev->dev, "buffer setup failed\n");