From 280e105f418b8fc9f19c18d76e76810d7605ab25 Mon Sep 17 00:00:00 2001
From: kjc <kjc@FreeBSD.org>
Date: Fri, 9 Oct 1998 11:48:22 +0000
Subject: fix a bug which could lock up a transmitter. don't use the entire
 buffer space.  if WRTX becomes equal to RDTX, the transmitter stops assuming
 the buffer is empty.

---
 sys/dev/en/midway.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

(limited to 'sys/dev/en')

diff --git a/sys/dev/en/midway.c b/sys/dev/en/midway.c
index 91b17b6..2e22fd1 100644
--- a/sys/dev/en/midway.c
+++ b/sys/dev/en/midway.c
@@ -2119,7 +2119,11 @@ again:
     goto dequeue_drop;
   }
 
-  if (launch.need > sc->txslot[chan].bfree) {
+  /*
+   * note: don't use the entire buffer space.  if WRTX becomes equal
+   * to RDTX, the transmitter stops assuming the buffer is empty!  --kjc
+   */
+  if (launch.need >= sc->txslot[chan].bfree) {
     EN_COUNT(sc->txoutspace);
 #ifdef EN_DEBUG
     printf("%s: tx%d: out of transmit space\n", sc->sc_dev.dv_xname, chan);
-- 
cgit v1.1