From 3116ce5265526e797b4a92f76ffbbc355ca7a277 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Wed, 23 Jul 2014 15:28:26 -0700
Subject: [PATCH] VAX8600: Fix for console I/O from Johnny Billquist

Writing to the TXCS register always updated the transmit enable mask, even when the "Write Mask Now" bit was not set. That bit needs to be set for the write to the register to actually update the transmit enable mask.
---
 VAX/vax860_stddev.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/VAX/vax860_stddev.c b/VAX/vax860_stddev.c
index ec404fb7..410ba1bd 100644
--- a/VAX/vax860_stddev.c
+++ b/VAX/vax860_stddev.c
@@ -55,8 +55,8 @@
 #define TXCS_V_TEN      16                              /* Transmitter en */
 #define TXCS_M_TEN      0xF
 #define TXCS_TEN        (TXCS_M_TEN << TXCS_V_TEN)
-#define TXCS_RD         (CSR_DONE + CSR_IE + TXCS_TEN + TXCS_IDC)  /* terminal output */
-#define TXCS_WR         (CSR_IE + TXCS_TEN)
+#define TXCS_RD         (CSR_DONE + CSR_IE + TXCS_TEN + TXCS_IDC + TXCS_WMN)  /* Readable bits */
+#define TXCS_WR         (CSR_IE)		        /* Writeable bits */
 #define ID_CT           0                               /* console terminal */
 #define ID_RS           1                               /* remote services */
 #define ID_EMM          2                               /* environmental monitoring module */
@@ -493,13 +493,16 @@ return (tto_csr & TXCS_RD);
 
 void txcs_wr (int32 data)
 {
-tto_csr = (tto_csr & ~TXCS_WR) | (data & TXCS_WR);
-if (data & TXCS_WMN)                                    /* updating mask? */
-    tto_update_int ();
-if ((data & CSR_IE) == 0)
+tto_csr = (tto_csr & ~TXCS_WR) | (data & TXCS_WR);          /* Write new bits. */
+if (data & TXCS_WMN) {                                      /* Updating enable mask? */
+    tto_csr = (tto_csr & ~TXCS_TEN) | (data & TXCS_TEN);    /* Yes. Modify enable mask. */
+    tto_update_int ();                                      /* This can change interrupt requests... */
+    }
+if ((tto_csr & CSR_IE) == 0)
     tto_int = 0;
-else if ((tto_csr & (CSR_DONE + CSR_IE)) == CSR_DONE)
-    tto_int = 1;
+else
+    if ((tto_csr & CSR_DONE) == CSR_DONE)
+        tto_int = 1;
 return;
 }