On 04/11/14 16:50, H Hartley Sweeten wrote:
Remove the private data member 'ai_sample_count' and use the comedi_async
'scans_done' member to detect the analog input end-of-acquisition.
Move the EOA check so it happens after adding the samples from the current
urb to the async buffer. This prevents the unnecessary resubmit of the urb
when the EOA occurs.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/usbdux.c | 22 ++++------------------
1 file changed, 4 insertions(+), 18 deletions(-)
diff --git a/drivers/staging/comedi/drivers/usbdux.c b/drivers/staging/comedi/drivers/usbdux.c
index 7782015..4737dbf 100644
--- a/drivers/staging/comedi/drivers/usbdux.c
+++ b/drivers/staging/comedi/drivers/usbdux.c
@@ -202,8 +202,6 @@ struct usbdux_private {
unsigned int ao_cmd_running:1;
unsigned int pwm_cmd_running:1;
- /* number of samples to acquire */
- int ai_sample_count;
/* time between samples in units of the timer */
unsigned int ai_timer;
unsigned int ao_timer;
@@ -263,14 +261,6 @@ static void usbduxsub_ai_handle_urb(struct comedi_device *dev,
if (devpriv->ai_counter == 0) {
devpriv->ai_counter = devpriv->ai_timer;
- if (cmd->stop_src == TRIG_COUNT) {
- devpriv->ai_sample_count--;
- if (devpriv->ai_sample_count < 0) {
- async->events |= COMEDI_CB_EOA;
- return;
- }
- }
-
/* get the data from the USB bus and hand it over to comedi */
for (i = 0; i < cmd->chanlist_len; i++) {
unsigned int range = CR_RANGE(cmd->chanlist[i]);
@@ -284,6 +274,10 @@ static void usbduxsub_ai_handle_urb(struct comedi_device *dev,
if (!comedi_buf_write_samples(s, &val, 1))
return;
}
+
+ if (cmd->stop_src == TRIG_COUNT &&
+ async->scans_done >= cmd->stop_arg)
+ async->events |= COMEDI_CB_EOA;
You could return early here, but it doesn't really matter as the
following code does nothing if COMEDI_CB_EOA is set.
}
/* if command is still running, resubmit urb */
@@ -732,14 +726,6 @@ static int usbdux_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->ai_counter = devpriv->ai_timer;
- if (cmd->stop_src == TRIG_COUNT) {
- /* data arrives as one packet */
- devpriv->ai_sample_count = cmd->stop_arg;
- } else {
- /* continous acquisition */
- devpriv->ai_sample_count = 0;
- }
-
if (cmd->start_src == TRIG_NOW) {
/* enable this acquisition operation */
devpriv->ai_cmd_running = 1;
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Web: http://www.mev.co.uk/ )=-
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