On Wed, 2012-05-09 at 19:33 +0800, Richard Zhao wrote: > 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 <[email protected]> Can you pls rebase this against the slave-dma next and resend. It fails to apply for me. > --- > 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; >
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