staging: comedi: cb_pcidas64: use comedi_async 'scans_done' to detect AO EOA

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

Use the comedi_nsamples_left() helper to get the number of samples to actually
read from the async buffer.

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/cb_pcidas64.c b/drivers/staging/comedi/drivers/cb_pcidas64.c
index 375bfbb60ebba4bd349897c09b7970d99317ee5e..05da5b33834ace803103c9a5551a4ebae8e89a68 100644 (file)
--- a/drivers/staging/comedi/drivers/cb_pcidas64.c
+++ b/drivers/staging/comedi/drivers/cb_pcidas64.c
@@ -1085,8 +1085,6 @@ struct pcidas64_private {
        dma_addr_t ao_dma_desc_bus_addr;
        /*  keeps track of buffer where the next ao sample should go */
        unsigned int ao_dma_index;
-       /*  number of analog output samples remaining */
-       unsigned long ao_count;
        unsigned int hw_revision;       /*  stc chip hardware revision number */
        /*  last bits sent to INTR_ENABLE_REG register */
        unsigned int intr_enable_bits;
@@ -2848,22 +2846,6 @@ static int last_ao_dma_load_completed(struct comedi_device *dev)
        return 1;
 }
 
-static int ao_stopped_by_error(struct comedi_device *dev,
-                              const struct comedi_cmd *cmd)
-{
-       struct pcidas64_private *devpriv = dev->private;
-
-       if (cmd->stop_src == TRIG_NONE)
-               return 1;
-       if (cmd->stop_src == TRIG_COUNT) {
-               if (devpriv->ao_count)
-                       return 1;
-               if (last_ao_dma_load_completed(dev) == 0)
-                       return 1;
-       }
-       return 0;
-}
-
 static inline int ao_dma_needs_restart(struct comedi_device *dev,
                                       unsigned short dma_status)
 {
@@ -2894,20 +2876,13 @@ static unsigned int cb_pcidas64_ao_fill_buffer(struct comedi_device *dev,
                                               unsigned short *dest,
                                               unsigned int max_bytes)
 {
-       struct pcidas64_private *devpriv = dev->private;
-       struct comedi_cmd *cmd = &s->async->cmd;
        unsigned int nsamples = comedi_bytes_to_samples(s, max_bytes);
        unsigned int actual_bytes;
 
-       if (cmd->stop_src == TRIG_COUNT && devpriv->ao_count < nsamples)
-               nsamples = devpriv->ao_count;
-
+       nsamples = comedi_nsamples_left(s, nsamples);
        actual_bytes = comedi_buf_read_samples(s, dest, nsamples);
-       nsamples = comedi_bytes_to_samples(s, actual_bytes);
-       if (cmd->stop_src == TRIG_COUNT)
-               devpriv->ao_count -= nsamples;
 
-       return nsamples;
+       return comedi_bytes_to_samples(s, actual_bytes);
 }
 
 static unsigned int load_ao_dma_buffer(struct comedi_device *dev,
@@ -3006,8 +2981,11 @@ static void handle_ao_interrupt(struct comedi_device *dev,
        }
 
        if ((status & DAC_DONE_BIT)) {
-               async->events |= COMEDI_CB_EOA;
-               if (ao_stopped_by_error(dev, cmd))
+               if ((cmd->stop_src == TRIG_COUNT &&
+                    async->scans_done >= cmd->stop_arg) ||
+                   last_ao_dma_load_completed(dev))
+                       async->events |= COMEDI_CB_EOA;
+               else
                        async->events |= COMEDI_CB_ERROR;
        }
        comedi_handle_events(dev, s);
@@ -3202,7 +3180,8 @@ static int prep_ao_dma(struct comedi_device *dev, const struct comedi_cmd *cmd)
                       devpriv->main_iobase + DAC_FIFO_REG);
        }
 
-       if (cmd->stop_src == TRIG_COUNT && devpriv->ao_count == 0)
+       if (cmd->stop_src == TRIG_COUNT &&
+           s->async->scans_done >= cmd->stop_arg)
                return 0;
 
        nbytes = load_ao_dma_buffer(dev, cmd);
@@ -3267,7 +3246,6 @@ static int ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
        writew(0x0, devpriv->main_iobase + DAC_CONTROL0_REG);
 
        devpriv->ao_dma_index = 0;
-       devpriv->ao_count = cmd->stop_arg * cmd->chanlist_len;
 
        set_dac_select_reg(dev, cmd);
        set_dac_interval_regs(dev, cmd);