Messages in this thread Patch in this message | | | From | Sascha Hauer <> | Subject | [PATCH 2/2] dmaengine i.MX SDMA: protect channel0 | Date | Mon, 6 Dec 2010 11:09:58 +0100 |
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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
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