From patchwork Fri Apr 27 07:02:55 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Richard Zhao X-Patchwork-Id: 155391 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 09D35B6F9D for ; Fri, 27 Apr 2012 17:06:14 +1000 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SNfDH-0008HJ-LJ; Fri, 27 Apr 2012 07:03:31 +0000 Received: from tx2ehsobe003.messaging.microsoft.com ([65.55.88.13] helo=tx2outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SNfD6-0008GR-HE for linux-arm-kernel@lists.infradead.org; Fri, 27 Apr 2012 07:03:22 +0000 Received: from mail86-tx2-R.bigfish.com (10.9.14.244) by TX2EHSOBE004.bigfish.com (10.9.40.24) with Microsoft SMTP Server id 14.1.225.23; Fri, 27 Apr 2012 07:03:17 +0000 Received: from mail86-tx2 (localhost [127.0.0.1]) by mail86-tx2-R.bigfish.com (Postfix) with ESMTP id DDF3E1A049E; Fri, 27 Apr 2012 07:03:16 +0000 (UTC) X-SpamScore: 0 X-BigFish: VS0(zzc89bhzz1202hzz8275bhz2dh2a8h668h839h93fhd24he5bh) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI Received: from mail86-tx2 (localhost.localdomain [127.0.0.1]) by mail86-tx2 (MessageSwitch) id 1335510194393900_11839; Fri, 27 Apr 2012 07:03:14 +0000 (UTC) Received: from TX2EHSMHS039.bigfish.com (unknown [10.9.14.244]) by mail86-tx2.bigfish.com (Postfix) with ESMTP id 4E371A0043; Fri, 27 Apr 2012 07:03:14 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by TX2EHSMHS039.bigfish.com (10.9.99.139) with Microsoft SMTP Server (TLS) id 14.1.225.23; Fri, 27 Apr 2012 07:03:14 +0000 Received: from az33smr01.freescale.net (10.64.34.199) by 039-SN1MMR1-003.039d.mgd.msft.net (10.84.1.16) with Microsoft SMTP Server id 14.1.355.3; Fri, 27 Apr 2012 02:03:15 -0500 Received: from b20223-02.ap.freescale.net (b20223-02.ap.freescale.net [10.192.242.124]) by az33smr01.freescale.net (8.13.1/8.13.0) with ESMTP id q3R737LJ008722; Fri, 27 Apr 2012 02:03:11 -0500 (CDT) From: Richard Zhao To: , , Subject: [PATCH 01/11] dma: imx-sdma: make channel0 operations atomic Date: Fri, 27 Apr 2012 15:02:55 +0800 Message-ID: <1335510185-7906-2-git-send-email-richard.zhao@freescale.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1335510185-7906-1-git-send-email-richard.zhao@freescale.com> References: <1335510185-7906-1-git-send-email-richard.zhao@freescale.com> MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-Spam-Note: CRM114 invocation failed X-Spam-Score: -4.2 (----) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-4.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [65.55.88.13 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: kernel@pengutronix.de, broonie@opensource.wolfsonmicro.com, w.sang@pengutronix.de, Richard Zhao , ben-linux@fluff.org, dan.j.williams@intel.com, shawn.guo@linaro.org, lrg@ti.com, =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org device_prep_dma_cyclic may be call in audio trigger function which is atomic context, so we make it atomic too. - change channel0 lock to spinlock. - Use polling to wait for channel0 finish running. Signed-off-by: Lothar Waßmann Signed-off-by: Richard Zhao --- drivers/dma/imx-sdma.c | 57 +++++++++++++++++++++++++++-------------------- 1 files changed, 33 insertions(+), 24 deletions(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index fddccae..fc49ffa 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -24,7 +24,7 @@ #include #include #include -#include +#include #include #include #include @@ -324,7 +324,7 @@ struct sdma_engine { struct dma_device dma_device; struct clk *clk_ipg; struct clk *clk_ahb; - struct mutex channel_0_lock; + spinlock_t channel_0_lock; struct sdma_script_start_addrs *script_addrs; }; @@ -402,19 +402,31 @@ static void sdma_enable_channel(struct sdma_engine *sdma, int channel) } /* - * sdma_run_channel - run a channel and wait till it's done + * sdma_run_channel0 - run a channel and wait till it's done */ -static int sdma_run_channel(struct sdma_channel *sdmac) +static int sdma_run_channel0(struct sdma_channel *sdmac) { struct sdma_engine *sdma = sdmac->sdma; int channel = sdmac->channel; int ret; + unsigned long timeout = 500; - init_completion(&sdmac->done); - + if (channel) + return -EINVAL; sdma_enable_channel(sdma, channel); - ret = wait_for_completion_timeout(&sdmac->done, HZ); + while (!(ret = readl_relaxed(sdma->regs + SDMA_H_INTR) & 1)) { + if (timeout-- <= 0) + break; + udelay(1); + } + + if (ret) { + /* Clear the interrupt status */ + writel_relaxed(ret, sdma->regs + SDMA_H_INTR); + } else { + dev_err(sdma->dev, "Timeout waiting for CH0 ready\n"); + } return ret ? 0 : -ETIMEDOUT; } @@ -426,17 +438,17 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size, void *buf_virt; dma_addr_t buf_phys; int ret; - - mutex_lock(&sdma->channel_0_lock); + unsigned long flags; buf_virt = dma_alloc_coherent(NULL, size, &buf_phys, GFP_KERNEL); if (!buf_virt) { - ret = -ENOMEM; - goto err_out; + return -ENOMEM; } + spin_lock_irqsave(&sdma->channel_0_lock, flags); + bd0->mode.command = C0_SETPM; bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD; bd0->mode.count = size / 2; @@ -445,12 +457,11 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size, memcpy(buf_virt, buf, size); - ret = sdma_run_channel(&sdma->channel[0]); + ret = sdma_run_channel0(&sdma->channel[0]); - dma_free_coherent(NULL, size, buf_virt, buf_phys); + spin_unlock_irqrestore(&sdma->channel_0_lock, flags); -err_out: - mutex_unlock(&sdma->channel_0_lock); + dma_free_coherent(NULL, size, buf_virt, buf_phys); return ret; } @@ -539,10 +550,6 @@ static void mxc_sdma_handle_channel(struct sdma_channel *sdmac) { complete(&sdmac->done); - /* not interested in channel 0 interrupts */ - if (sdmac->channel == 0) - return; - if (sdmac->flags & IMX_DMA_SG_LOOP) sdma_handle_channel_loop(sdmac); else @@ -555,6 +562,8 @@ static irqreturn_t sdma_int_handler(int irq, void *dev_id) unsigned long stat; stat = readl_relaxed(sdma->regs + SDMA_H_INTR); + /* not interested in channel 0 interrupts */ + stat &= ~1; writel_relaxed(stat, sdma->regs + SDMA_H_INTR); while (stat) { @@ -660,6 +669,7 @@ static int sdma_load_context(struct sdma_channel *sdmac) struct sdma_context_data *context = sdma->context; struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd; int ret; + unsigned long flags; if (sdmac->direction == DMA_DEV_TO_MEM) { load_address = sdmac->pc_from_device; @@ -677,7 +687,7 @@ static int sdma_load_context(struct sdma_channel *sdmac) dev_dbg(sdma->dev, "event_mask0 = 0x%08x\n", (u32)sdmac->event_mask[0]); dev_dbg(sdma->dev, "event_mask1 = 0x%08x\n", (u32)sdmac->event_mask[1]); - mutex_lock(&sdma->channel_0_lock); + spin_lock_irqsave(&sdma->channel_0_lock, flags); memset(context, 0, sizeof(*context)); context->channel_state.pc = load_address; @@ -696,10 +706,9 @@ static int sdma_load_context(struct sdma_channel *sdmac) bd0->mode.count = sizeof(*context) / 4; bd0->buffer_addr = sdma->context_phys; bd0->ext_buffer_addr = 2048 + (sizeof(*context) / 4) * channel; + ret = sdma_run_channel0(&sdma->channel[0]); - ret = sdma_run_channel(&sdma->channel[0]); - - mutex_unlock(&sdma->channel_0_lock); + spin_unlock_irqrestore(&sdma->channel_0_lock, flags); return ret; } @@ -1305,7 +1314,7 @@ static int __init sdma_probe(struct platform_device *pdev) if (!sdma) return -ENOMEM; - mutex_init(&sdma->channel_0_lock); + spin_lock_init(&sdma->channel_0_lock); sdma->dev = &pdev->dev;