From patchwork Fri May 1 13:21:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 226513 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=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 29123C47258 for ; Fri, 1 May 2020 13:56:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A48320836 for ; Fri, 1 May 2020 13:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588341394; bh=zP6VMlI64hQJZ2DTc28nD5ZTBc7aTru+OwhbaEP1Fzo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GEUmrbPsnE6H+aBS2pxIY9hJCXRmH+hxXn8RzUE/lvngUU3kCOrSX1IqyUw/NLIq5 eX+ACYlIu9ttEGlZ+lgYtuNqqI73vuIC5RwX6KUz3eWfNo2jtjkSGnH6NdxpkLk3aw XvTkjWEFlo2wHpILCoJku1YBQHQlI4isE1bgED7s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730567AbgEAN4V (ORCPT ); Fri, 1 May 2020 09:56:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:57778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729617AbgEANcp (ORCPT ); Fri, 1 May 2020 09:32:45 -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 84C95208C3; Fri, 1 May 2020 13:32:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339965; bh=zP6VMlI64hQJZ2DTc28nD5ZTBc7aTru+OwhbaEP1Fzo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yxSPRgx/3qh2ZyDMItRul/3XdPrfrHyR8mhOpIyKpWYXXc9UDeachBej5Y50ji0Be qhB5lJiL3aAiN+ZdHKfEgyx5quXV/GK2xopEa6WjCXjUWZvgSyBpOzG4mw+O5/wuoS KwoOxf0t6v8mJhI55Hbq8e1AGTRBJoO2vLY3NPPI= 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 4.14 038/117] iio: adc: stm32-adc: fix sleep in atomic context Date: Fri, 1 May 2020 15:21:14 +0200 Message-Id: <20200501131549.294100823@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131544.291247695@linuxfoundation.org> References: <20200501131544.291247695@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 @@ -1311,8 +1311,30 @@ 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) @@ -1648,6 +1670,7 @@ 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; @@ -1730,9 +1753,11 @@ static int stm32_adc_probe(struct platfo if (ret < 0) goto err_clk_disable; + 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");