From patchwork Wed Feb 24 08:20:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sascha Hauer X-Patchwork-Id: 8402631 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4372B9F2F0 for ; Wed, 24 Feb 2016 08:20:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C110C20303 for ; Wed, 24 Feb 2016 08:20:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C61DC2035D for ; Wed, 24 Feb 2016 08:20:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757812AbcBXIUl (ORCPT ); Wed, 24 Feb 2016 03:20:41 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:51279 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756950AbcBXIUj (ORCPT ); Wed, 24 Feb 2016 03:20:39 -0500 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1aYUgY-0004A6-8y; Wed, 24 Feb 2016 09:20:38 +0100 Received: from sha by dude.hi.pengutronix.de with local (Exim 4.86) (envelope-from ) id 1aYUgX-0002Zn-GL; Wed, 24 Feb 2016 09:20:37 +0100 From: Sascha Hauer To: linux-spi@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Mark Brown , Anton Bondarenko , Sascha Hauer Subject: [PATCH 1/9] spi: imx: drop fallback to PIO Date: Wed, 24 Feb 2016 09:20:25 +0100 Message-Id: <1456302033-25638-2-git-send-email-s.hauer@pengutronix.de> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1456302033-25638-1-git-send-email-s.hauer@pengutronix.de> References: <1456302033-25638-1-git-send-email-s.hauer@pengutronix.de> X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-spi@vger.kernel.org Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP At the moment the driver decides to fallback to PIO mode the buffers are already mapped for DMA. It's a bug to access them with the CPU afterwards, so we cannot just fallback to PIO mode. It should not be necessary anyway, since we only use DMA when we verified that it's possible in the fist place, so when prep_slave_sg fails it's a bug, either in the SDMA driver or in the can_dma implementation. Signed-off-by: Sascha Hauer --- drivers/spi/spi-imx.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 6497fc9..a61b1b1 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -945,7 +945,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, tx->sgl, tx->nents, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc_tx) - goto tx_nodma; + return -EINVAL; desc_tx->callback = spi_imx_dma_tx_callback; desc_tx->callback_param = (void *)spi_imx; @@ -956,8 +956,10 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, desc_rx = dmaengine_prep_slave_sg(master->dma_rx, rx->sgl, rx->nents, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc_rx) - goto rx_nodma; + if (!desc_rx) { + dmaengine_terminate_all(master->dma_tx); + return -EINVAL; + } desc_rx->callback = spi_imx_dma_rx_callback; desc_rx->callback_param = (void *)spi_imx; @@ -1010,12 +1012,6 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, ret = transfer->len; return ret; - -rx_nodma: - dmaengine_terminate_all(master->dma_tx); -tx_nodma: - dev_warn_once(spi_imx->dev, "DMA not available, falling back to PIO\n"); - return -EAGAIN; } static int spi_imx_pio_transfer(struct spi_device *spi, @@ -1042,15 +1038,12 @@ static int spi_imx_pio_transfer(struct spi_device *spi, static int spi_imx_transfer(struct spi_device *spi, struct spi_transfer *transfer) { - int ret; struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); if (spi_imx->bitbang.master->can_dma && spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) { spi_imx->usedma = true; - ret = spi_imx_dma_transfer(spi_imx, transfer); - if (ret != -EAGAIN) - return ret; + return spi_imx_dma_transfer(spi_imx, transfer); } spi_imx->usedma = false;