Disable processing of output data after disabling scroll lock by force.

The syscons code disabled scroll lock inside sc_cnputs() if it's going
to print a system message. The code currently wants to process any TTY
output data as well, but we cannot do this, because the TTY lock is a
sleep mutex, while cnputs() picks up a spin mutex.

Disable the code for now. It solves a panic when a console message is
printed while scroll lock is enabled. One solution would be to
initialize a task structure here.

Reported by:	Paul B. Mahol <onemda gmail com>

1 files changed, 9 insertions, 0 deletions

diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 3c83adb..37b08b6 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -1509,7 +1509,9 @@ sc_cnputc(struct consdev *cd, int c)
     scr_stat *scp = sc_console;
     void *save;
 #ifndef SC_NO_HISTORY
+#if 0
     struct tty *tp;
+#endif
 #endif /* !SC_NO_HISTORY */
     int s;
 
@@ -1526,11 +1528,18 @@ sc_cnputc(struct consdev *cd, int c)
 	    scp->status |= CURSOR_ENABLED;
 	    sc_draw_cursor_image(scp);
 	}
+#if 0
+	/*
+	 * XXX: Now that TTY's have their own locks, we cannot process
+	 * any data after disabling scroll lock. cnputs already holds a
+	 * spinlock.
+	 */
 	tp = SC_DEV(scp->sc, scp->index);
 	tty_lock(tp);
 	if (tty_opened(tp))
 	    sctty_outwakeup(tp);
 	tty_unlock(tp);
+#endif
     }
 #endif /* !SC_NO_HISTORY */