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Commit 7877445b authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: dt282x: introduce dt282x_isadma_disable() 



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: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f609c29d

drivers/staging/comedi/drivers/dt282x.c

+14 −4
Original line number Diff line number Diff line
@@ -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);