diff options
Diffstat (limited to 'drivers/dma/imx-sdma.c')
| -rw-r--r-- | drivers/dma/imx-sdma.c | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index e93c4ea1a1a8..9de94344a97f 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -32,6 +32,7 @@ #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/dmaengine.h> +#include <linux/delay.h> #include <asm/irq.h> #include <mach/sdma.h> @@ -278,6 +279,7 @@ struct sdma_channel { enum dma_status status; unsigned int chn_count; unsigned int chn_real_count; + unsigned int irq_handling; }; #define MAX_DMA_CHANNELS 32 @@ -324,6 +326,7 @@ struct sdma_engine { struct dma_device dma_device; struct clk *clk; struct sdma_script_start_addrs *script_addrs; + spinlock_t irq_reg_lock; }; #define SDMA_H_CONFIG_DSPDMA (1 << 12) /* indicates if the DSPDMA is used */ @@ -537,18 +540,33 @@ static void mxc_sdma_handle_channel(struct sdma_channel *sdmac) static irqreturn_t sdma_int_handler(int irq, void *dev_id) { struct sdma_engine *sdma = dev_id; - u32 stat; + struct sdma_channel *sdmac; + unsigned long flag; + int channel; + u32 stat, stat_bak; + spin_lock_irqsave(&sdma->irq_reg_lock, flag); stat = readl_relaxed(sdma->regs + SDMA_H_INTR); writel_relaxed(stat, sdma->regs + SDMA_H_INTR); + spin_unlock_irqrestore(&sdma->irq_reg_lock, flag); + + stat_bak = stat; + while (stat_bak) { + channel = fls(stat_bak) - 1; + sdmac = &sdma->channel[channel]; + sdmac->irq_handling = 1; + stat_bak &= ~(1 << channel); + } while (stat) { - int channel = fls(stat) - 1; - struct sdma_channel *sdmac = &sdma->channel[channel]; + channel = fls(stat) - 1; + sdmac = &sdma->channel[channel]; - mxc_sdma_handle_channel(sdmac); + if (sdmac->irq_handling) + mxc_sdma_handle_channel(sdmac); stat &= ~(1 << channel); + sdmac->irq_handling = 0; } return IRQ_HANDLED; @@ -878,6 +896,8 @@ static int sdma_request_channel(struct sdma_channel *sdmac) sdmac->buf_tail = 0; + sdmac->irq_handling = 0; + return 0; out: @@ -973,11 +993,41 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan) return 0; } +static void sdma_irq_pending_check(struct sdma_channel *sdmac) +{ + struct sdma_engine *sdma = sdmac->sdma; + unsigned long flag; + u32 stat; + + spin_lock_irqsave(&sdma->irq_reg_lock, flag); + stat = readl_relaxed(sdma->regs + SDMA_H_INTR); + + /*Check if the current channel's IRQ hasn't been responded*/ + if (stat & (1 << sdmac->channel)) { + /*Handle the irq manually*/ + writel_relaxed(1 << sdmac->channel, sdma->regs + SDMA_H_INTR); + spin_unlock_irqrestore(&sdma->irq_reg_lock, flag); + + /*Prevent irq_handler from doing handle_channel() again*/ + sdmac->irq_handling = 0; + mxc_sdma_handle_channel(sdmac); + } else { + spin_unlock_irqrestore(&sdma->irq_reg_lock, flag); + } + + /*Wait here until irq_handler's finished*/ + while (sdmac->irq_handling) + udelay(100); +} + static void sdma_free_chan_resources(struct dma_chan *chan) { struct sdma_channel *sdmac = to_sdma_chan(chan); struct sdma_engine *sdma = sdmac->sdma; + /*Check if irq to the channel is still pending*/ + sdma_irq_pending_check(sdmac); + sdma_disable_channel(sdmac); if (sdmac->event_id0) @@ -1449,6 +1499,8 @@ static int __init sdma_probe(struct platform_device *pdev) dma_cap_set(DMA_SLAVE, sdma->dma_device.cap_mask); dma_cap_set(DMA_CYCLIC, sdma->dma_device.cap_mask); + spin_lock_init(&sdma->irq_reg_lock); + INIT_LIST_HEAD(&sdma->dma_device.channels); /* Initialize channel parameters */ for (i = 0; i < MAX_DMA_CHANNELS; i++) { |