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authorSascha Hauer <s.hauer@pengutronix.de>2011-08-25 11:03:35 +0200
committerVinod Koul <vinod.koul@intel.com>2011-08-29 20:08:26 +0530
commit73eab978ad6934499b83ecc920d470fe99c5e54d (patch)
tree1f622269c883e767832a365557c2c504a3fd2fc3
parent981ed70d8e4faf3689dbf3c48868a31d5b004d7a (diff)
downloadop-kernel-dev-73eab978ad6934499b83ecc920d470fe99c5e54d.zip
op-kernel-dev-73eab978ad6934499b83ecc920d470fe99c5e54d.tar.gz
dmaengine i.MX SDMA: lock channel 0
channel0 of the sdma engine is the configuration channel. It is a shared resource and thus must be protected by a mutex. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
-rw-r--r--drivers/dma/imx-sdma.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 7bd7e98..f50c87c 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -318,6 +318,7 @@ struct sdma_engine {
dma_addr_t context_phys;
struct dma_device dma_device;
struct clk *clk;
+ struct mutex channel_0_lock;
struct sdma_script_start_addrs *script_addrs;
};
@@ -415,11 +416,15 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
dma_addr_t buf_phys;
int ret;
+ mutex_lock(&sdma->channel_0_lock);
+
buf_virt = dma_alloc_coherent(NULL,
size,
&buf_phys, GFP_KERNEL);
- if (!buf_virt)
- return -ENOMEM;
+ if (!buf_virt) {
+ ret = -ENOMEM;
+ goto err_out;
+ }
bd0->mode.command = C0_SETPM;
bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
@@ -433,6 +438,9 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
dma_free_coherent(NULL, size, buf_virt, buf_phys);
+err_out:
+ mutex_unlock(&sdma->channel_0_lock);
+
return ret;
}
@@ -656,6 +664,8 @@ static int sdma_load_context(struct sdma_channel *sdmac)
dev_dbg(sdma->dev, "event_mask0 = 0x%08x\n", sdmac->event_mask0);
dev_dbg(sdma->dev, "event_mask1 = 0x%08x\n", sdmac->event_mask1);
+ mutex_lock(&sdma->channel_0_lock);
+
memset(context, 0, sizeof(*context));
context->channel_state.pc = load_address;
@@ -676,6 +686,8 @@ static int sdma_load_context(struct sdma_channel *sdmac)
ret = sdma_run_channel(&sdma->channel[0]);
+ mutex_unlock(&sdma->channel_0_lock);
+
return ret;
}
@@ -1274,6 +1286,8 @@ static int __init sdma_probe(struct platform_device *pdev)
if (!sdma)
return -ENOMEM;
+ mutex_init(&sdma->channel_0_lock);
+
sdma->dev = &pdev->dev;
iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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