Removed buffer preloading from comedi_write_v22(). Apps must now

use start_src=TRIG_INT, issue the command, then cause an internal
trigger.

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 5310716d3efc52df10a4f2e04d6d3f3acf86e081..b998b46e00fd891f3dee2789068484feeaa9c1ff 100644 (file)
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -1363,8 +1363,6 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
        int n,m,count=0,retval=0;
        DECLARE_WAITQUEUE(wait,current);
        int sample_size;
-       void *buf_ptr;
-       unsigned int buf_len;
 
        dev=comedi_get_device_by_minor(MINOR(RDEV_OF_FILE(file)));
 
@@ -1388,24 +1386,11 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
 
        if(!nbytes)return 0;
 
-       if(!(s->subdev_flags&SDF_WRITEABLE))
-               return -EIO;
-
-       if(!s->busy){
-               /* XXX this is going to change soon -- write cmds
-                * will require start_src=TRIG_FOLLOW */
-               buf_ptr=async->prealloc_buf;
-               buf_len=async->prealloc_bufsz;
-       }else{
-               if(s->busy != file)
-                       return -EACCES;
-
-               buf_ptr=async->data;
-               buf_len=async->data_len;
-       }
+       if(!s->busy)
+               return 0;
 
-       if(!buf_ptr)
-               return -EIO;
+       if(s->busy != file)
+               return -EACCES;
 
        add_wait_queue(&dev->write_wait,&wait);
        while(nbytes>0 && !retval){
@@ -1413,10 +1398,12 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
 
                n=nbytes;
 
-               m=buf_len-(async->buf_user_count-async->buf_int_count);
-               if(async->buf_user_ptr+m > buf_len){
-                       m=buf_len - async->buf_user_ptr;
+               m=async->data_len+async->buf_int_count-async->buf_user_count;
+
+               if(async->buf_user_ptr+m > async->data_len){
+                       m=async->data_len - async->buf_user_ptr;
                }
+
                if(m<n)n=m;
 
                if(n==0){
@@ -1435,7 +1422,7 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
                        schedule();
                        continue;
                }
-               m=copy_from_user(buf_ptr+async->buf_user_ptr,buf,n);
+               m=copy_from_user(async->data+async->buf_user_ptr,buf,n);
                if(m) retval=-EFAULT;
                n-=m;
                
@@ -1444,7 +1431,7 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
                async->buf_user_ptr+=n;
                async->buf_user_count+=n;
 
-               if(async->buf_user_ptr>=buf_len ){
+               if(async->buf_user_ptr>=async->data_len ){
                        async->buf_user_ptr=0;
                }