diff options
author | Richard Zhao <richard.zhao@freescale.com> | 2012-05-11 15:14:27 +0800 |
---|---|---|
committer | Vinod Koul <vinod.koul@linux.intel.com> | 2012-05-11 14:00:38 +0530 |
commit | 2ccaef0520d18d0072153f090d4110b4075c332c (patch) | |
tree | c4fcc9cbac1f7448263701ae5c5926f28351935c /drivers/dma/imx-sdma.c | |
parent | 922ee08baad2052d0759f100e026d49798c51fef (diff) | |
download | linux-2ccaef0520d18d0072153f090d4110b4075c332c.tar.bz2 |
dma: imx-sdma: make channel0 operations atomic
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>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma/imx-sdma.c')
-rw-r--r-- | 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 cd0619a897ff..a472a29d8497 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 { dma_addr_t context_phys; struct dma_device dma_device; struct clk *clk; - 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; } @@ -541,10 +548,6 @@ static void sdma_tasklet(unsigned long data) 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 @@ -557,6 +560,8 @@ 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) { @@ -662,6 +667,7 @@ 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; @@ -679,7 +685,7 @@ 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; @@ -698,10 +704,9 @@ 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; } @@ -1300,7 +1305,7 @@ 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; |