staging: comedi: quatech_daqp_cs: use comedi_async 'scans_done' to detect EOA

Remove the private data member 'count' and use the comedi_async 'scans_done'
member to detect the end-of-acquisition.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
index 0630df3..f77485b 100644 (file)
--- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
+++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
@@ -65,8 +65,6 @@ struct daqp_private {
        enum { semaphore, buffer } interrupt_mode;
 
        struct completion eos;
-
-       int count;
 };
 
 /* The DAQP communicates with the system through a 16 byte I/O window. */
@@ -194,6 +192,7 @@ static enum irqreturn daqp_interrupt(int irq, void *dev_id)
        struct comedi_device *dev = dev_id;
        struct daqp_private *devpriv = dev->private;
        struct comedi_subdevice *s = dev->read_subdev;
+       struct comedi_cmd *cmd = &s->async->cmd;
        int loop_limit = 10000;
        int status;
 
@@ -227,12 +226,10 @@ static enum irqreturn daqp_interrupt(int irq, void *dev_id)
                         * and stop conversion if zero
                         */
 
-                       if (devpriv->count > 0) {
-                               devpriv->count--;
-                               if (devpriv->count == 0) {
-                                       s->async->events |= COMEDI_CB_EOA;
-                                       break;
-                               }
+                       if (cmd->stop_src == TRIG_COUNT &&
+                           s->async->scans_done >= cmd->stop_arg) {
+                               s->async->events |= COMEDI_CB_EOA;
+                               break;
                        }
 
                        if ((loop_limit--) <= 0)
@@ -573,12 +570,16 @@ static int daqp_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
         */
 
        if (cmd->stop_src == TRIG_COUNT) {
-               devpriv->count = cmd->stop_arg * cmd->scan_end_arg;
-               threshold = 2 * devpriv->count;
-               while (threshold > DAQP_FIFO_SIZE * 3 / 4)
-                       threshold /= 2;
+               unsigned long long nsamples;
+               unsigned long long nbytes;
+
+               nsamples = (unsigned long long)cmd->stop_arg *
+                          cmd->scan_end_arg;
+               nbytes = nsamples * comedi_bytes_per_sample(s);
+               while (nbytes > DAQP_FIFO_SIZE * 3 / 4)
+                       nbytes /= 2;
+               threshold = nbytes;
        } else {
-               devpriv->count = -1;
                threshold = DAQP_FIFO_SIZE / 2;
        }