device_prep_dma_cyclic may be call in audio trigger function which is atomic context, so we make it atomic too.
- change channel0 lock to spinlock. - Use polling to wait for channel0 finish running.
Signed-off-by: Richard Zhao richard.zhao@freescale.com --- drivers/dma/imx-sdma.c | 57 ++++++++++++++++++++++++++--------------------- 1 files changed, 31 insertions(+), 26 deletions(-)
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index fddccae..4fd48eb 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -24,7 +24,7 @@ #include <linux/mm.h> #include <linux/interrupt.h> #include <linux/clk.h> -#include <linux/wait.h> +#include <linux/delay.h> #include <linux/sched.h> #include <linux/semaphore.h> #include <linux/spinlock.h> @@ -324,7 +324,7 @@ struct sdma_engine { struct dma_device dma_device; struct clk *clk_ipg; struct clk *clk_ahb; - struct mutex channel_0_lock; + spinlock_t channel_0_lock; struct sdma_script_start_addrs *script_addrs; };
@@ -402,19 +402,27 @@ static void sdma_enable_channel(struct sdma_engine *sdma, int channel) }
/* - * sdma_run_channel - run a channel and wait till it's done + * sdma_run_channel0 - run a channel and wait till it's done */ -static int sdma_run_channel(struct sdma_channel *sdmac) +static int sdma_run_channel0(struct sdma_engine *sdma) { - struct sdma_engine *sdma = sdmac->sdma; - int channel = sdmac->channel; int ret; + unsigned long timeout = 500;
- init_completion(&sdmac->done); + sdma_enable_channel(sdma, 0);
- sdma_enable_channel(sdma, channel); + while (!(ret = readl_relaxed(sdma->regs + SDMA_H_INTR) & 1)) { + if (timeout-- <= 0) + break; + udelay(1); + }
- ret = wait_for_completion_timeout(&sdmac->done, HZ); + if (ret) { + /* Clear the interrupt status */ + writel_relaxed(ret, sdma->regs + SDMA_H_INTR); + } else { + dev_err(sdma->dev, "Timeout waiting for CH0 ready\n"); + }
return ret ? 0 : -ETIMEDOUT; } @@ -426,17 +434,17 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size, void *buf_virt; dma_addr_t buf_phys; int ret; - - mutex_lock(&sdma->channel_0_lock); + unsigned long flags;
buf_virt = dma_alloc_coherent(NULL, size, &buf_phys, GFP_KERNEL); if (!buf_virt) { - ret = -ENOMEM; - goto err_out; + return -ENOMEM; }
+ spin_lock_irqsave(&sdma->channel_0_lock, flags); + bd0->mode.command = C0_SETPM; bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD; bd0->mode.count = size / 2; @@ -445,12 +453,11 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
memcpy(buf_virt, buf, size);
- ret = sdma_run_channel(&sdma->channel[0]); + ret = sdma_run_channel0(sdma);
- dma_free_coherent(NULL, size, buf_virt, buf_phys); + spin_unlock_irqrestore(&sdma->channel_0_lock, flags);
-err_out: - mutex_unlock(&sdma->channel_0_lock); + dma_free_coherent(NULL, size, buf_virt, buf_phys);
return ret; } @@ -539,10 +546,6 @@ static void mxc_sdma_handle_channel(struct sdma_channel *sdmac) { complete(&sdmac->done);
- /* not interested in channel 0 interrupts */ - if (sdmac->channel == 0) - return; - if (sdmac->flags & IMX_DMA_SG_LOOP) sdma_handle_channel_loop(sdmac); else @@ -555,6 +558,8 @@ static irqreturn_t sdma_int_handler(int irq, void *dev_id) unsigned long stat;
stat = readl_relaxed(sdma->regs + SDMA_H_INTR); + /* not interested in channel 0 interrupts */ + stat &= ~1; writel_relaxed(stat, sdma->regs + SDMA_H_INTR);
while (stat) { @@ -660,6 +665,7 @@ static int sdma_load_context(struct sdma_channel *sdmac) struct sdma_context_data *context = sdma->context; struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd; int ret; + unsigned long flags;
if (sdmac->direction == DMA_DEV_TO_MEM) { load_address = sdmac->pc_from_device; @@ -677,7 +683,7 @@ static int sdma_load_context(struct sdma_channel *sdmac) dev_dbg(sdma->dev, "event_mask0 = 0x%08x\n", (u32)sdmac->event_mask[0]); dev_dbg(sdma->dev, "event_mask1 = 0x%08x\n", (u32)sdmac->event_mask[1]);
- mutex_lock(&sdma->channel_0_lock); + spin_lock_irqsave(&sdma->channel_0_lock, flags);
memset(context, 0, sizeof(*context)); context->channel_state.pc = load_address; @@ -696,10 +702,9 @@ static int sdma_load_context(struct sdma_channel *sdmac) bd0->mode.count = sizeof(*context) / 4; bd0->buffer_addr = sdma->context_phys; bd0->ext_buffer_addr = 2048 + (sizeof(*context) / 4) * channel; + ret = sdma_run_channel0(sdma);
- ret = sdma_run_channel(&sdma->channel[0]); - - mutex_unlock(&sdma->channel_0_lock); + spin_unlock_irqrestore(&sdma->channel_0_lock, flags);
return ret; } @@ -1305,7 +1310,7 @@ static int __init sdma_probe(struct platform_device *pdev) if (!sdma) return -ENOMEM;
- mutex_init(&sdma->channel_0_lock); + spin_lock_init(&sdma->channel_0_lock);
sdma->dev = &pdev->dev;