Merge branch 'master' of ssh://rtime.felk.cvut.cz/lisovros/pcan_lin

[linux-lin.git] / sllin / sllin.c

diff --git a/sllin/sllin.c b/sllin/sllin.c
index 64eb10b62cf9b711ad641467055a79c1d2a24396..a0bb1e513b92c4a400f7c88732b61841531adfba 100644 (file)
--- a/sllin/sllin.c
+++ b/sllin/sllin.c
@@ -478,10 +478,22 @@ int sllin_setup_msg(struct sllin *sl, int mode, int id,
        sl->tx_lim = SLLIN_BUFF_DATA;
 
        if ((data != NULL) && len) {
+               int i;
+               unsigned csum  = 0;
+
                sl->tx_lim += len;
                memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
+               /* compute data parity there */
+               for (i = SLLIN_BUFF_DATA; i < sl->tx_lim; i++) {
+                       csum += sl->tx_buff[i];
+                       if (csum > 255)
+                               csum -= 255;
+               }
+
+               sl->tx_buff[sl->tx_lim++] = csum;
        }
-       sl->rx_lim += len;
+       if (len != 0)
+               sl->rx_lim += len + 1;
 
        return 0;
 }