fix problems with buffer wrap-around by using generic comedi_fc code

diff --git a/comedi/drivers/dt282x.c b/comedi/drivers/dt282x.c
index b043852319a378d8f41164203fc01183b137e09a..93e697d573f52903e08d8838f4f7453192875723 100644 (file)
--- a/comedi/drivers/dt282x.c
+++ b/comedi/drivers/dt282x.c
@@ -58,6 +58,7 @@ Notes:
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
 #include <asm/dma.h>
+#include "comedi_fc.h"
 
 #define DEBUG
 
@@ -382,14 +383,13 @@ static int dt282x_ns_to_timer(int *nanosec,int round_mode);
 
 static int dt282x_grab_dma(comedi_device *dev,int dma1,int dma2);
 
-static void dt282x_copy_to_buffer(comedi_device *dev,sampl_t *buf,
+static void dt282x_munge(comedi_device *dev,sampl_t *buf,
        unsigned int nbytes)
 {
        comedi_async *async = dev->subdevices[0].async;
        unsigned int i;
        unsigned short mask=(1<<boardtype.adbits)-1;
        unsigned short sign=1<<(boardtype.adbits-1);
-       unsigned short *abuf;
        int n;
 
        if(devpriv->ad_2scomp){
@@ -398,19 +398,11 @@ static void dt282x_copy_to_buffer(comedi_device *dev,sampl_t *buf,
                sign = 0;
        }
 
-       abuf = async->prealloc_buf + async->buf_write_ptr;
-       if(async->buf_write_ptr + nbytes >= async->prealloc_bufsz){
-               n = (async->prealloc_bufsz - async->buf_write_ptr - nbytes)/2;
-               for(i=0;i<n;i++){
-                       abuf[i] = (buf[i]&mask)^sign;
-               }
-               nbytes -= n;
-               abuf = async->prealloc_buf;
-               buf = buf + i;
-       }
+       if( nbytes % 2 )
+               comedi_error( dev, "bug! odd number of bytes from dma xfer" );
        n = nbytes/2;
        for(i=0;i<n;i++){
-               abuf[i] = (buf[i]&mask)^sign;
+               buf[i] = (buf[i]&mask)^sign;
        }
 }
 
@@ -476,15 +468,9 @@ static void dt282x_ai_dma_interrupt(comedi_device * dev)
 
        devpriv->current_dma_chan = 1-i;
 
-       ret = comedi_buf_write_alloc(s->async, size);
-       if(!ret){
-               rt_printk("dt282x: AI buffer overflow\n");
-               s->async->events |= COMEDI_CB_OVERFLOW;
-               comedi_event(dev,s,s->async->events);
-               return;
-       }
-       dt282x_copy_to_buffer(dev, ptr, size);
-       comedi_buf_write_free(s->async, size);
+       dt282x_munge(dev, ptr, size );
+       ret = cfc_write_array_to_buffer( s, ptr, size );
+       if( ret == 0 ) return;
 
        devpriv->nread-=size/2;