diff options
| author | Thierry Bultel <tbultel@pixelsurmer.com> | 2018-03-05 14:27:18 +0100 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2018-03-05 15:03:47 +0100 |
| commit | 2746e2c389f9d50043d21e2204270403efb9d62f (patch) | |
| tree | 3004e9ec5637564c18bb3a8841ae52ba73949ef3 /drivers/dma/imx-sdma.c | |
| parent | Linux 4.16-rc1 (diff) | |
| download | linux-2746e2c389f9d50043d21e2204270403efb9d62f.tar.xz linux-2746e2c389f9d50043d21e2204270403efb9d62f.zip | |
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: Thierry Bultel <tbultel@pixelsurmer.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/imx-sdma.c')
| -rw-r--r-- | drivers/dma/imx-sdma.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index e7db24c67030..ccd03c3cedfe 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -338,6 +338,7 @@ 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) @@ -596,7 +597,14 @@ static int sdma_config_ownership(struct sdma_channel *sdmac, 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); + + 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) struct sdma_buffer_descriptor *bd; int error = 0; 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 @@ -938,10 +954,15 @@ 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; writel_relaxed(BIT(channel), sdma->regs + SDMA_H_STATSTOP); sdmac->status = DMA_ERROR; + spin_lock_irqsave(&sdmac->lock, flags); + sdmac->enabled = false; + spin_unlock_irqrestore(&sdmac->lock, flags); + return 0; } |