moved increment of buf_int_count to beginning of comedi_buf_put*() to eliminate race

with buffer overrun check.  Added setting of COMEDI_CB_BLOCK to comedi_buf_put() so
it doesn't need to be set in drivers

diff --git a/include/linux/comedidev.h b/include/linux/comedidev.h
index d59dd372c20d62f13a562ea681f04e62b9947f57..5c46d17278f80ca8fde2ec7e3249ccfec4668b19 100644 (file)
--- a/include/linux/comedidev.h
+++ b/include/linux/comedidev.h
@@ -307,6 +307,7 @@ static inline int alloc_private(comedi_device *dev,int size)
 // writes a data point to comedi's buffer, used for input
 static inline void comedi_buf_put(comedi_async *async, sampl_t x)
 {
+       async->buf_int_count += sizeof(sampl_t);
        *(sampl_t *)(async->data + async->buf_int_ptr) = x;
        async->buf_int_ptr += sizeof(sampl_t);
        if(async->buf_int_ptr >= async->data_len){
@@ -317,11 +318,11 @@ static inline void comedi_buf_put(comedi_async *async, sampl_t x)
                async->cur_chan = 0;
                async->events |= COMEDI_CB_EOS;
        }
-       async->buf_int_count += sizeof(sampl_t);
+       async->events |= COMEDI_CB_BLOCK;
 }
 
 /* Writes an array of data points to comedi's buffer, used for input.
- * Can be more efficient than comedi_buf_put() */
+ * Can be more efficient than putting comedi_buf_put() in a loop. */
 static inline void comedi_buf_put_array(comedi_async *async, sampl_t* array, unsigned int length)
 {
        unsigned int num_bytes;
@@ -329,6 +330,7 @@ static inline void comedi_buf_put_array(comedi_async *async, sampl_t* array, uns
 
        while((num_bytes = length * sizeof(sampl_t) - xfer_count))
        {
+               async->buf_int_count += num_bytes;
                if( async->buf_int_ptr + num_bytes > async->data_len)
                        num_bytes = async->data_len - async->buf_int_ptr;
 
@@ -346,7 +348,6 @@ static inline void comedi_buf_put_array(comedi_async *async, sampl_t* array, uns
                        async->cur_chan %= async->cmd.chanlist_len;
                        async->events |= COMEDI_CB_EOS;
                }
-               async->buf_int_count += num_bytes;
                xfer_count += num_bytes;
        }
        async->events |= COMEDI_CB_BLOCK;