According to Documentation/DMA-ISA-LPC.txt, the DMA lock needs to be
claimed before using any of the ISA DMA routines. Introduce a helper
function to disable the ISA DMA controller and add the necessary
locking calls.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/dt282x.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c
index 2d01c6c..54c679a 100644
--- a/drivers/staging/comedi/drivers/dt282x.c
+++ b/drivers/staging/comedi/drivers/dt282x.c
@@ -339,6 +339,15 @@ static void dt282x_isadma_program(struct dt282x_dma_desc *dma)
release_dma_lock(flags);
}
+static void dt282x_isadma_disable(struct dt282x_dma_desc *dma)
+{
+ unsigned long flags;
+
+ flags = claim_dma_lock();
+ disable_dma(dma->chan);
+ release_dma_lock(flags);
+}
+
static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)
{
struct dt282x_private *devpriv = dev->private;
@@ -377,9 +386,10 @@ static int dt282x_prep_ao_dma(struct comedi_device *dev, int dma_index, int n)
static void dt282x_disable_dma(struct comedi_device *dev)
{
struct dt282x_private *devpriv = dev->private;
+ int i;
- disable_dma(devpriv->dma_desc[0].chan);
- disable_dma(devpriv->dma_desc[1].chan);
+ for (i = 0; i < 2; i++)
+ dt282x_isadma_disable(&devpriv->dma_desc[i]);
}
static unsigned int dt282x_ns_to_timer(unsigned int *ns, unsigned int flags)
@@ -463,7 +473,7 @@ static void dt282x_ao_dma_interrupt(struct comedi_device *dev,
outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE,
dev->iobase + DT2821_SUPCSR_REG);
- disable_dma(dma->chan);
+ dt282x_isadma_disable(dma);
if (!dt282x_ao_setup_dma(dev, s, devpriv->cur_dma))
s->async->events |= COMEDI_CB_OVERFLOW;
@@ -482,7 +492,7 @@ static void dt282x_ai_dma_interrupt(struct comedi_device *dev,
outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE,
dev->iobase + DT2821_SUPCSR_REG);
- disable_dma(dma->chan);
+ dt282x_isadma_disable(dma);
dt282x_munge(dev, s, dma->virt_addr, dma->size);
ret = comedi_buf_write_samples(s, dma->virt_addr, nsamples);
--
2.0.3
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