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 <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/pcl816.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/pcl816.c
b/drivers/staging/comedi/drivers/pcl816.c
index e0d91a1..d2ce775 100644
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -147,6 +147,15 @@ static void pcl816_isadma_program(unsigned int dma_chan,
release_dma_lock(flags);
}
+static void pcl816_isadma_disable(unsigned int dma_chan)
+{
+ unsigned long flags;
+
+ flags = claim_dma_lock();
+ disable_dma(dma_chan);
+ release_dma_lock(flags);
+}
+
static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters)
{
struct pcl816_private *devpriv = dev->private;
@@ -202,7 +211,7 @@ static void pcl816_ai_setup_next_dma(struct comedi_device
*dev,
struct comedi_cmd *cmd = &s->async->cmd;
struct pcl816_dma_desc *dma;
- disable_dma(devpriv->dma);
+ pcl816_isadma_disable(devpriv->dma);
if (devpriv->dma_runs_to_end > -1 || cmd->stop_src == TRIG_NONE) {
/* switch dma bufs */
devpriv->cur_dma = 1 - devpriv->cur_dma;
--
2.0.3
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