From patchwork Fri Jul 11 16:06:42 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 4536171 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 [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7EE5B9F1C4 for ; Fri, 11 Jul 2014 16:06:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 891562018B for ; Fri, 11 Jul 2014 16:06:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90C6F20256 for ; Fri, 11 Jul 2014 16:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754615AbaGKQGt (ORCPT ); Fri, 11 Jul 2014 12:06:49 -0400 Received: from xavier.telenet-ops.be ([195.130.132.52]:52398 "EHLO xavier.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753910AbaGKQGr (ORCPT ); Fri, 11 Jul 2014 12:06:47 -0400 Received: from ayla.of.borg ([84.193.72.141]) by xavier.telenet-ops.be with bizsmtp id R46k1o00Y32ts5g0146kTK; Fri, 11 Jul 2014 18:06:45 +0200 Received: from geert by ayla.of.borg with local (Exim 4.76) (envelope-from ) id 1X5dLQ-0003kr-DY; Fri, 11 Jul 2014 18:06:44 +0200 From: Geert Uytterhoeven To: Mark Brown Cc: Laurent Pinchart , linux-spi@vger.kernel.org, dmaengine@vger.kernel.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH 2/2] spi: sh-msiof: Fix leaking of unused DMA descriptors Date: Fri, 11 Jul 2014 18:06:42 +0200 Message-Id: <1405094802-14401-2-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1405094802-14401-1-git-send-email-geert+renesas@glider.be> References: <1405094802-14401-1-git-send-email-geert+renesas@glider.be> Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Spam-Status: No, score=-7.5 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 If dmaengine_prep_slave_sg() or dmaengine_submit() fail, we may leak unused DMA descriptors. As per Documentation/dmaengine.txt, once a DMA descriptor has been obtained, it must be submitted. Hence: - First prepare and submit all DMA descriptors, - Prepare the SPI controller for DMA, - Start DMA by calling dma_async_issue_pending(), - Make sure to call dmaengine_terminate_all() on all descriptors that haven't completed. Reported-by: Laurent Pinchart Signed-off-by: Geert Uytterhoeven --- drivers/spi/spi-sh-msiof.c | 71 +++++++++++++++++++++++++--------------------- 1 file changed, 38 insertions(+), 33 deletions(-) diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c index 2a4354dcd661..887c2084130f 100644 --- a/drivers/spi/spi-sh-msiof.c +++ b/drivers/spi/spi-sh-msiof.c @@ -636,48 +636,38 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx, dma_cookie_t cookie; int ret; - if (tx) { - ier_bits |= IER_TDREQE | IER_TDMAE; - dma_sync_single_for_device(p->master->dma_tx->device->dev, - p->tx_dma_addr, len, DMA_TO_DEVICE); - desc_tx = dmaengine_prep_slave_single(p->master->dma_tx, - p->tx_dma_addr, len, DMA_TO_DEVICE, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc_tx) - return -EAGAIN; - } - + /* First prepare and submit the DMA request(s), as this may fail */ if (rx) { ier_bits |= IER_RDREQE | IER_RDMAE; desc_rx = dmaengine_prep_slave_single(p->master->dma_rx, p->rx_dma_addr, len, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc_rx) - return -EAGAIN; - } - - /* 1 stage FIFO watermarks for DMA */ - sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1); - - /* setup msiof transfer mode registers (32-bit words) */ - sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4); - - sh_msiof_write(p, IER, ier_bits); - - reinit_completion(&p->done); + if (!desc_rx) { + ret = -EAGAIN; + goto no_dma_rx; + } - if (rx) { desc_rx->callback = sh_msiof_dma_complete; desc_rx->callback_param = p; cookie = dmaengine_submit(desc_rx); if (dma_submit_error(cookie)) { ret = cookie; - goto stop_ier; + goto no_dma_rx; } - dma_async_issue_pending(p->master->dma_rx); } if (tx) { + ier_bits |= IER_TDREQE | IER_TDMAE; + dma_sync_single_for_device(p->master->dma_tx->device->dev, + p->tx_dma_addr, len, DMA_TO_DEVICE); + desc_tx = dmaengine_prep_slave_single(p->master->dma_tx, + p->tx_dma_addr, len, DMA_TO_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_tx) { + ret = -EAGAIN; + goto no_dma_tx; + } + if (rx) { /* No callback */ desc_tx->callback = NULL; @@ -688,15 +678,30 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx, cookie = dmaengine_submit(desc_tx); if (dma_submit_error(cookie)) { ret = cookie; - goto stop_rx; + goto no_dma_tx; } - dma_async_issue_pending(p->master->dma_tx); } + /* 1 stage FIFO watermarks for DMA */ + sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1); + + /* setup msiof transfer mode registers (32-bit words) */ + sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4); + + sh_msiof_write(p, IER, ier_bits); + + reinit_completion(&p->done); + + /* Now start DMA */ + if (tx) + dma_async_issue_pending(p->master->dma_rx); + if (rx) + dma_async_issue_pending(p->master->dma_tx); + ret = sh_msiof_spi_start(p, rx); if (ret) { dev_err(&p->pdev->dev, "failed to start hardware\n"); - goto stop_tx; + goto stop_dma; } /* wait for tx fifo to be emptied / rx fifo to be filled */ @@ -726,14 +731,14 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx, stop_reset: sh_msiof_reset_str(p); sh_msiof_spi_stop(p, rx); -stop_tx: +stop_dma: if (tx) dmaengine_terminate_all(p->master->dma_tx); -stop_rx: +no_dma_tx: if (rx) dmaengine_terminate_all(p->master->dma_rx); -stop_ier: sh_msiof_write(p, IER, 0); +no_dma_rx: return ret; }