From: Sascha Hauer <s.hauer@pengutronix.de>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
Dan Williams <dan.j.williams@intel.com>,
Sascha Hauer <s.hauer@pengutronix.de>
Subject: [PATCH 2/2] dmaengine i.MX SDMA: protect channel0
Date: Mon, 6 Dec 2010 11:09:58 +0100 [thread overview]
Message-ID: <1291630198-9690-3-git-send-email-s.hauer@pengutronix.de> (raw)
In-Reply-To: <1291630198-9690-1-git-send-email-s.hauer@pengutronix.de>
Channel 0 of the SDMA engine is a shared resource used by the
other channels, thus we have to protect it with a mutex.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
drivers/dma/imx-sdma.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 01c4a5f..b1f5947 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -355,6 +355,7 @@ struct sdma_engine {
struct dma_device dma_device;
struct clk *clk;
struct sdma_script_start_addrs *script_addrs;
+ struct mutex channel0_mutex;
};
#define SDMA_H_CONFIG_DSPDMA (1 << 12) /* indicates if the DSPDMA is used */
@@ -437,6 +438,8 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
if (!buf_virt)
return -ENOMEM;
+ mutex_lock(&sdma->channel0_mutex);
+
bd0->mode.command = C0_SETPM;
bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
bd0->mode.count = size / 2;
@@ -447,6 +450,8 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
ret = sdma_run_channel(&sdma->channel[0]);
+ mutex_unlock(&sdma->channel0_mutex);
+
dma_free_coherent(NULL, size, buf_virt, buf_phys);
return ret;
@@ -684,6 +689,8 @@ static int sdma_load_context(struct sdma_channel *sdmac)
context->gReg[6] = sdmac->shp_addr;
context->gReg[7] = sdmac->watermark_level;
+ mutex_lock(&sdma->channel0_mutex);
+
bd0->mode.command = C0_SETDM;
bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
bd0->mode.count = sizeof(*context) / 4;
@@ -692,6 +699,8 @@ static int sdma_load_context(struct sdma_channel *sdmac)
ret = sdma_run_channel(&sdma->channel[0]);
+ mutex_unlock(&sdma->channel0_mutex);
+
return ret;
}
@@ -1297,6 +1306,8 @@ static int __init sdma_probe(struct platform_device *pdev)
sdma->version = pdata->sdma_version;
+ mutex_init(&sdma->channel0_mutex);
+
INIT_LIST_HEAD(&sdma->dma_device.channels);
/* Initialize channel parameters */
for (i = 0; i < MAX_DMA_CHANNELS; i++) {
--
1.7.2.3
next prev parent reply other threads:[~2010-12-06 10:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-06 10:09 [PATCH for -rc] dmaengine: i.MX SDMA fixes Sascha Hauer
2010-12-06 10:09 ` [PATCH 1/2] dmaengine i.MX SDMA: initialize on module_init Sascha Hauer
2010-12-07 23:31 ` Dan Williams
2010-12-06 10:09 ` Sascha Hauer [this message]
2010-12-07 23:50 ` [PATCH 2/2] dmaengine i.MX SDMA: protect channel0 Dan Williams
2010-12-09 14:50 ` Sascha Hauer
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