From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753921AbdFWM4i (ORCPT ); Fri, 23 Jun 2017 08:56:38 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:40711 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751182AbdFWM4g (ORCPT ); Fri, 23 Jun 2017 08:56:36 -0400 From: Amelie Delaunay To: Mark Brown , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre Torgue CC: , , , , Amelie Delaunay Subject: [PATCH 7/8] spi: stm32: enhance DMA error management Date: Fri, 23 Jun 2017 14:55:49 +0200 Message-ID: <1498222550-19092-8-git-send-email-amelie.delaunay@st.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1498222550-19092-1-git-send-email-amelie.delaunay@st.com> References: <1498222550-19092-1-git-send-email-amelie.delaunay@st.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.201.23.160] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-23_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch reworks DMA error management. In case the DMA callback is called while EOT (End Of Transfer) flag is not set, that means that DMA encountered an error. This error will result in an auto-suspend of SPI flow, which could also result in an overrun. So, in DMA mode, SUSP and OVR flags are a condition to stop the current transfer. Signed-off-by: Amelie Delaunay --- drivers/spi/spi-stm32.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 209afda..63af9d9 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -514,6 +514,12 @@ static irqreturn_t stm32_spi_irq(int irq, void *dev_id) dev_warn(spi->dev, "Communication suspended\n"); if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) stm32_spi_read_rxfifo(spi, false); + /* + * If communication is suspended while using DMA, it means + * that something went wrong, so stop the current transfer + */ + if (spi->cur_usedma) + end = true; } if (sr & SPI_SR_MODF) { @@ -525,6 +531,12 @@ static irqreturn_t stm32_spi_irq(int irq, void *dev_id) dev_warn(spi->dev, "Overrun: received value discarded\n"); if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) stm32_spi_read_rxfifo(spi, false); + /* + * If overrun is detected while using DMA, it means that + * something went wrong, so stop the current transfer + */ + if (spi->cur_usedma) + end = true; } if (sr & SPI_SR_EOT) { @@ -645,12 +657,10 @@ static void stm32_spi_dma_cb(void *data) spin_unlock_irqrestore(&spi->lock, flags); - if (!(sr & SPI_SR_EOT)) { - dev_warn(spi->dev, "DMA callback (sr=0x%08x)\n", sr); + if (!(sr & SPI_SR_EOT)) + dev_warn(spi->dev, "DMA error (sr=0x%08x)\n", sr); - spi_finalize_current_transfer(spi->master); - stm32_spi_disable(spi); - } + /* Now wait for EOT, or SUSP or OVR in case of error */ } /** -- 1.9.1