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Commit bed8d538 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl818: introduce pcl818_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 9cf2765f

drivers/staging/comedi/drivers/pcl818.c

+12 −3
Original line number Diff line number Diff line
@@ -342,6 +342,15 @@ static void pcl818_isadma_program(unsigned int dma_chan, 
	release_dma_lock(flags);

}



static void pcl818_isadma_disable(unsigned int dma_chan)

{

	unsigned long flags;



	flags = claim_dma_lock();

	disable_dma(dma_chan);

	release_dma_lock(flags);

}



static void pcl818_start_pacer(struct comedi_device *dev, bool load_counters)

{

	struct pcl818_private *devpriv = dev->private;
@@ -364,7 +373,7 @@ static void pcl818_ai_setup_dma(struct comedi_device *dev, 
	struct pcl818_dma_desc *dma = &devpriv->dma_desc[0];

	struct comedi_cmd *cmd = &s->async->cmd;



	disable_dma(devpriv->dma);	/*  disable dma */

	pcl818_isadma_disable(devpriv->dma);

	if (cmd->stop_src == TRIG_COUNT) {

		dma->size = cmd->stop_arg * comedi_bytes_per_scan(s);

		devpriv->dma_runs_to_end = dma->size / devpriv->hwdmasize;
@@ -388,7 +397,7 @@ static void pcl818_ai_setup_next_dma(struct comedi_device *dev, 
	struct comedi_cmd *cmd = &s->async->cmd;

	struct pcl818_dma_desc *dma;



	disable_dma(devpriv->dma);

	pcl818_isadma_disable(devpriv->dma);

	devpriv->cur_dma = 1 - devpriv->cur_dma;

	if (devpriv->dma_runs_to_end > -1 || cmd->stop_src == TRIG_NONE) {

		/* switch dma bufs */
@@ -879,7 +888,7 @@ static int pcl818_ai_cancel(struct comedi_device *dev, 
				return 0;

			}

		}

		disable_dma(devpriv->dma);

		pcl818_isadma_disable(devpriv->dma);

	}



	outb(PCL818_CTRL_DISABLE_TRIG, dev->iobase + PCL818_CTRL_REG);