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@xxxxxxxxxxxxx>
---
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;
--
1.7.5.4
--
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