@@ -327,6 +327,7 @@ struct sdma_channel {
unsigned int chn_real_count;
struct tasklet_struct tasklet;
struct imx_dma_data data;
+ bool enabled;
};
#define IMX_DMA_SG_LOOP BIT(0)
@@ -562,7 +563,13 @@ static int sdma_config_ownership(struct sdma_channel *sdmac,
static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
{
+ struct sdma_channel *sdmac = &sdma->channel[channel];
+ unsigned long flags;
+
+ spin_lock_irqsave(&sdmac->lock, flags);
+ sdmac->enabled = true;
writel(BIT(channel), sdma->regs + SDMA_H_START);
+ spin_unlock_irqrestore(&sdmac->lock, flags);
}
/*
@@ -740,9 +747,12 @@ static irqreturn_t sdma_int_handler(int irq, void *dev_id)
int channel = fls(stat) - 1;
struct sdma_channel *sdmac = &sdma->channel[channel];
- tasklet_schedule(&sdmac->tasklet);
+ spin_lock(&sdmac->lock);
+ if (sdmac->enabled)
+ tasklet_schedule(&sdmac->tasklet);
__clear_bit(channel, &stat);
+ spin_unlock(&sdmac->lock);
}
return IRQ_HANDLED;
@@ -906,9 +916,13 @@ static int sdma_disable_channel(struct dma_chan *chan)
struct sdma_channel *sdmac = to_sdma_chan(chan);
struct sdma_engine *sdma = sdmac->sdma;
int channel = sdmac->channel;
+ unsigned long flags;
+ spin_lock_irqsave(&sdmac->lock, flags);
+ sdmac->enabled = false;
writel_relaxed(BIT(channel), sdma->regs + SDMA_H_STATSTOP);
sdmac->status = DMA_ERROR;
+ spin_unlock_irqrestore(&sdmac->lock, flags);
return 0;
}
There is race between STOP of SDMA channel and finish of SDMA transfer, so some times, even after sdma_disable_channel() is called, the bit of 'terminated channel' in INTR may still get asserted, thus cause an extra sdma tasklet be called. Add flag 'enabled' to each sdma channel to indicate its state. only when SDMA channel is in its enabled state, irq handler can schedule a sdma tasklet for it. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> --- drivers/dma/imx-sdma.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)