diff --git a/arch/arm/mach-tegra/dma.c b/arch/arm/mach-tegra/dma.c index bd4f62a613aa..e945ae28ee77 100644 --- a/arch/arm/mach-tegra/dma.c +++ b/arch/arm/mach-tegra/dma.c @@ -127,6 +127,7 @@ struct tegra_dma_channel { #define NV_DMA_MAX_CHANNELS 32 +static bool tegra_dma_initialized; static DEFINE_MUTEX(tegra_dma_lock); static DECLARE_BITMAP(channel_usage, NV_DMA_MAX_CHANNELS); @@ -352,6 +353,9 @@ struct tegra_dma_channel *tegra_dma_allocate_channel(int mode) int channel; struct tegra_dma_channel *ch = NULL; + if (WARN_ON(!tegra_dma_initialized)) + return NULL; + mutex_lock(&tegra_dma_lock); /* first channel is the shared channel */ @@ -678,6 +682,8 @@ int __init tegra_dma_init(void) void __iomem *addr; struct clk *c; + bitmap_fill(channel_usage, NV_DMA_MAX_CHANNELS); + c = clk_get_sys("tegra-dma", NULL); if (IS_ERR(c)) { pr_err("Unable to get clock for APB DMA\n"); @@ -696,18 +702,9 @@ int __init tegra_dma_init(void) writel(0xFFFFFFFFul >> (31 - TEGRA_SYSTEM_DMA_CH_MAX), addr + APB_DMA_IRQ_MASK_SET); - memset(channel_usage, 0, sizeof(channel_usage)); - memset(dma_channels, 0, sizeof(dma_channels)); - - /* Reserve all the channels we are not supposed to touch */ - for (i = 0; i < TEGRA_SYSTEM_DMA_CH_MIN; i++) - __set_bit(i, channel_usage); - for (i = TEGRA_SYSTEM_DMA_CH_MIN; i <= TEGRA_SYSTEM_DMA_CH_MAX; i++) { struct tegra_dma_channel *ch = &dma_channels[i]; - __clear_bit(i, channel_usage); - ch->id = i; snprintf(ch->name, TEGRA_DMA_NAME_SIZE, "dma_channel_%d", i); @@ -726,14 +723,15 @@ int __init tegra_dma_init(void) goto fail; } ch->irq = irq; + + __clear_bit(i, channel_usage); } /* mark the shared channel allocated */ __set_bit(TEGRA_SYSTEM_DMA_CH_MIN, channel_usage); - for (i = TEGRA_SYSTEM_DMA_CH_MAX+1; i < NV_DMA_MAX_CHANNELS; i++) - __set_bit(i, channel_usage); + tegra_dma_initialized = true; - return ret; + return 0; fail: writel(0, addr + APB_DMA_GEN); for (i = TEGRA_SYSTEM_DMA_CH_MIN; i <= TEGRA_SYSTEM_DMA_CH_MAX; i++) {