Commit 2746e2c3 authored by Thierry Bultel's avatar Thierry Bultel Committed by Vinod Koul

dmaengine: imx-sdma: fix pagefault when channel is disabled during interrupt

Add a spinlock and a 'enabled' boolean on channel descriptor, to avoid
using buffer descriptors in the interrupt context,
when sdma_disable_channel is called meanwhile.
Signed-off-by: default avatarThierry Bultel <tbultel@pixelsurmer.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 7928b2cb
...@@ -338,6 +338,7 @@ struct sdma_channel { ...@@ -338,6 +338,7 @@ struct sdma_channel {
unsigned int chn_real_count; unsigned int chn_real_count;
struct tasklet_struct tasklet; struct tasklet_struct tasklet;
struct imx_dma_data data; struct imx_dma_data data;
bool enabled;
}; };
#define IMX_DMA_SG_LOOP BIT(0) #define IMX_DMA_SG_LOOP BIT(0)
...@@ -596,7 +597,14 @@ static int sdma_config_ownership(struct sdma_channel *sdmac, ...@@ -596,7 +597,14 @@ static int sdma_config_ownership(struct sdma_channel *sdmac,
static void sdma_enable_channel(struct sdma_engine *sdma, int channel) static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
{ {
unsigned long flags;
struct sdma_channel *sdmac = &sdma->channel[channel];
writel(BIT(channel), sdma->regs + SDMA_H_START); writel(BIT(channel), sdma->regs + SDMA_H_START);
spin_lock_irqsave(&sdmac->lock, flags);
sdmac->enabled = true;
spin_unlock_irqrestore(&sdmac->lock, flags);
} }
/* /*
...@@ -685,6 +693,14 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) ...@@ -685,6 +693,14 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac)
struct sdma_buffer_descriptor *bd; struct sdma_buffer_descriptor *bd;
int error = 0; int error = 0;
enum dma_status old_status = sdmac->status; enum dma_status old_status = sdmac->status;
unsigned long flags;
spin_lock_irqsave(&sdmac->lock, flags);
if (!sdmac->enabled) {
spin_unlock_irqrestore(&sdmac->lock, flags);
return;
}
spin_unlock_irqrestore(&sdmac->lock, flags);
/* /*
* loop mode. Iterate over descriptors, re-setup them and * loop mode. Iterate over descriptors, re-setup them and
...@@ -938,10 +954,15 @@ static int sdma_disable_channel(struct dma_chan *chan) ...@@ -938,10 +954,15 @@ static int sdma_disable_channel(struct dma_chan *chan)
struct sdma_channel *sdmac = to_sdma_chan(chan); struct sdma_channel *sdmac = to_sdma_chan(chan);
struct sdma_engine *sdma = sdmac->sdma; struct sdma_engine *sdma = sdmac->sdma;
int channel = sdmac->channel; int channel = sdmac->channel;
unsigned long flags;
writel_relaxed(BIT(channel), sdma->regs + SDMA_H_STATSTOP); writel_relaxed(BIT(channel), sdma->regs + SDMA_H_STATSTOP);
sdmac->status = DMA_ERROR; sdmac->status = DMA_ERROR;
spin_lock_irqsave(&sdmac->lock, flags);
sdmac->enabled = false;
spin_unlock_irqrestore(&sdmac->lock, flags);
return 0; return 0;
} }
......
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