run spl6 for dz SAE

[unix-history] / usr / src / sys / kern / tty.c

diff --git a/usr/src/sys/kern/tty.c b/usr/src/sys/kern/tty.c
index 675990c..3ca2d55 100644 (file)
--- a/usr/src/sys/kern/tty.c
+++ b/usr/src/sys/kern/tty.c
@@ -1,4 +1,4 @@
-/*     tty.c   3.2     %H%     */
+/*     tty.c   3.3     %H%     */

 
 /*
  * general TTY subroutines
 
 /*
  * general TTY subroutines


@@ -18,6 +18,17 @@
 
 char   partab[];
 
 
 char   partab[];
 

+/*
+ * When running dz's using only SAE (silo alarm) on input
+ * it is necessary to call dzrint() at clock interrupt time.
+ * This is unsafe unless spl5()s in tty code are changed to
+ * spl6()s to block clock interrupts.  Note that the dh driver
+ * currently in use works the same way as the dz, even though
+ * we could try to more intelligently manage its silo.
+ * Thus don't take this out if you have no dz's unless you
+ * change clock.c and dhtimer().
+ */
+#define        spl5    spl6

 
 /*
  * Input mapping table-- if an entry is non-zero, when the
 
 /*
  * Input mapping table-- if an entry is non-zero, when the