This functions uses the async->cur_chan to determine if the current channel
is using a bipolar range and the sample needs to be munged. The cur_chan is
never incremented so all the samples are munged based on the fist channel
in the cmd->chanlist.
Bump the cur_chan after writing each sample. This fixes the code so that
the munging will be done correctly.
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/rtd520.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/rtd520.c
b/drivers/staging/comedi/drivers/rtd520.c
index 888238e..8e87655 100644
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -606,6 +606,8 @@ static int ai_read_n(struct comedi_device *dev, struct
comedi_subdevice *s,
int count)
{
struct rtd_private *devpriv = dev->private;
+ struct comedi_async *async = s->async;
+ struct comedi_cmd *cmd = &async->cmd;
int ii;
for (ii = 0; ii < count; ii++) {
@@ -618,7 +620,7 @@ static int ai_read_n(struct comedi_device *dev, struct
comedi_subdevice *s,
d = readw(devpriv->las1 + LAS1_ADC_FIFO);
d = d >> 3; /* low 3 bits are marker lines */
- if (test_bit(s->async->cur_chan, devpriv->chan_is_bipolar))
+ if (test_bit(async->cur_chan, devpriv->chan_is_bipolar))
/* convert to comedi unsigned data */
d = comedi_offset_munge(s, d);
d &= s->maxdata;
@@ -626,6 +628,9 @@ static int ai_read_n(struct comedi_device *dev, struct
comedi_subdevice *s,
if (!comedi_buf_write_samples(s, &d, 1))
return -1;
+ async->cur_chan++;
+ async->cur_chan %= cmd->chanlist_len;
+
if (devpriv->ai_count > 0) /* < 0, means read forever */
devpriv->ai_count--;
}
--
2.0.3
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