From patchwork Mon Sep 14 12:26:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 7175391 Return-Path: X-Original-To: patchwork-dmaengine@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 1C6E49F314 for ; Mon, 14 Sep 2015 12:26:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 26AB820705 for ; Mon, 14 Sep 2015 12:26:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6BF482073F for ; Mon, 14 Sep 2015 12:26:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752694AbbINM0W (ORCPT ); Mon, 14 Sep 2015 08:26:22 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:53099 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437AbbINM0T (ORCPT ); Mon, 14 Sep 2015 08:26:19 -0400 Received: from avalon.pp.htv.fi (85-23-193-79.bb.dnainternet.fi [85.23.193.79]) by galahad.ideasonboard.com (Postfix) with ESMTPSA id 35EAB20066; Mon, 14 Sep 2015 14:26:16 +0200 (CEST) From: Laurent Pinchart To: dmaengine@vger.kernel.org Cc: linux-sh@vger.kernel.org, Kuninori Morimoto Subject: [PATCH] dmaengine: rcar-dmac: Wait for IRQs completion when freeing channel Date: Mon, 14 Sep 2015 15:26:13 +0300 Message-Id: <1442233573-26684-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> X-Mailer: git-send-email 2.4.6 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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 When freeing channel resources we need to ensure that no IRQ will occur for the given channel. In order to do so the driver stops the hardware, but an IRQ handler could still be running, especially given that the channel IRQ is threaded. Fix it by waiting for pending IRQs completion with synchronize_irq() Signed-off-by: Laurent Pinchart --- drivers/dma/sh/rcar-dmac.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) Hi Morimoto-san, This patch is compile-tested only. Would you be able to check if it fixes the issue you've reported with SDHI and rcar-dmac ? diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 7820d07e7bee..da50c8f4d533 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -121,6 +121,7 @@ struct rcar_dmac_desc_page { * struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel * @chan: base DMA channel object * @iomem: channel I/O memory base + * @irq: channel IRQ number * @index: index of this channel in the controller * @src_xfer_size: size (in bytes) of hardware transfers on the source side * @dst_xfer_size: size (in bytes) of hardware transfers on the destination side @@ -140,6 +141,7 @@ struct rcar_dmac_desc_page { struct rcar_dmac_chan { struct dma_chan chan; void __iomem *iomem; + int irq; unsigned int index; unsigned int src_xfer_size; @@ -726,6 +728,15 @@ static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); } +static void rcar_dmac_chan_halt_and_wait(struct rcar_dmac_chan *chan) +{ + spin_lock_irq(&chan->lock); + rcar_dmac_chan_halt(chan); + spin_unlock_irq(&chan->lock); + + synchronize_irq(chan->irq); +} + static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc, *_desc; @@ -972,9 +983,7 @@ static void rcar_dmac_free_chan_resources(struct dma_chan *chan) LIST_HEAD(list); /* Protect against ISR */ - spin_lock_irq(&rchan->lock); - rcar_dmac_chan_halt(rchan); - spin_unlock_irq(&rchan->lock); + rcar_dmac_chan_halt_and_wait(rchan); /* Now no new interrupts will occur */ @@ -1121,17 +1130,8 @@ static int rcar_dmac_device_config(struct dma_chan *chan, static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); - unsigned long flags; - - spin_lock_irqsave(&rchan->lock, flags); - rcar_dmac_chan_halt(rchan); - spin_unlock_irqrestore(&rchan->lock, flags); - - /* - * FIXME: No new interrupt can occur now, but the IRQ thread might still - * be running. - */ + rcar_dmac_chan_halt_and_wait(rchan); rcar_dmac_chan_reinit(rchan); return 0; @@ -1524,7 +1524,6 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, struct dma_chan *chan = &rchan->chan; char pdev_irqname[5]; char *irqname; - int irq; int ret; rchan->index = index; @@ -1541,8 +1540,8 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, /* Request the channel interrupt. */ sprintf(pdev_irqname, "ch%u", index); - irq = platform_get_irq_byname(pdev, pdev_irqname); - if (irq < 0) { + rchan->irq = platform_get_irq_byname(pdev, pdev_irqname); + if (rchan->irq < 0) { dev_err(dmac->dev, "no IRQ specified for channel %u\n", index); return -ENODEV; } @@ -1552,11 +1551,13 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, if (!irqname) return -ENOMEM; - ret = devm_request_threaded_irq(dmac->dev, irq, rcar_dmac_isr_channel, + ret = devm_request_threaded_irq(dmac->dev, rchan->irq, + rcar_dmac_isr_channel, rcar_dmac_isr_channel_thread, 0, irqname, rchan); if (ret) { - dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", irq, ret); + dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", + rchan->irq, ret); return ret; }