From 3c5d2c7facf8715cb14802fb082720db350bace9 Mon Sep 17 00:00:00 2001
From: msaitoh <msaitoh@NetBSD.org>
Date: Fri, 29 Sep 2000 08:08:37 +0000
Subject: [PATCH] avoid SH7709A's serious bug (it fails to read IPR* registers
 under particular circumstances)

---
 sys/arch/evbsh3/conf/COMPUTEXEVB |  4 +--
 sys/arch/evbsh3/evbsh3/shb.c     | 46 ++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/sys/arch/evbsh3/conf/COMPUTEXEVB b/sys/arch/evbsh3/conf/COMPUTEXEVB
index 3e75affcde6b..362ac7fe2868 100644
--- a/sys/arch/evbsh3/conf/COMPUTEXEVB
+++ b/sys/arch/evbsh3/conf/COMPUTEXEVB
@@ -1,4 +1,4 @@
-#	$NetBSD: COMPUTEXEVB,v 1.7 2000/09/26 22:20:03 msaitoh Exp $
+#	$NetBSD: COMPUTEXEVB,v 1.8 2000/09/29 08:08:38 msaitoh Exp $
 #
 #	GENERIC -- everything that's currently supported
 #
@@ -14,7 +14,7 @@ options 	MINIROOTSIZE=3074	# size of memory disk, in blocks
 maxusers	32		# estimated number of users
 
 # CPU support.  At least one is REQUIRED.
-options		SH7709A		# 100MHz
+options		SH7709A,SH7709A_BROKEN_IPR	# 100MHz
 options		PCLOCK=25000000		# 25.000MHz
 options		IOM_ROM_BEGIN=0x00000000
 options		IOM_ROM_SIZE=0x00100000	# 1MB
diff --git a/sys/arch/evbsh3/evbsh3/shb.c b/sys/arch/evbsh3/evbsh3/shb.c
index c3653c0c3ece..855962f617d8 100644
--- a/sys/arch/evbsh3/evbsh3/shb.c
+++ b/sys/arch/evbsh3/evbsh3/shb.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: shb.c,v 1.11 2000/08/17 13:07:51 msaitoh Exp $	*/
+/*	$NetBSD: shb.c,v 1.12 2000/09/29 08:08:37 msaitoh Exp $	*/
 
 /*-
  * Copyright (c) 1993, 1994 Charles Hannum.  All rights reserved.
@@ -375,7 +375,6 @@ fakeintr(arg)
 
 #define	IRQ_BIT(irq_num)	(1 << (irq_num))
 
-
 /*ARGSUSED*/
 int	/* 1 = check ipending on return, 0 = fast intr return */
 intrhandler(p1, p2, p3, p4, frame)
@@ -502,20 +501,48 @@ check_ipending(p1, p2, p3, p4, frame)
 }
 
 #if !defined(SH4)
+
+#ifdef SH7709A_BROKEN_IPR	/* broken IPR patch */
+
+#define IPRA	0
+#define IPRB	1
+#define IPRC	2
+#define IPRD	3
+#define IPRE	4
+
+static unsigned short ipr[ 5 ];
+
+#endif /* SH7709A_BROKEN_IPR */
+
 void
 mask_irq(irq)
 	int irq;
 {
 	switch (irq) {
 	case TMU1_IRQ:
+#ifdef SH7709A_BROKEN_IPR
+		ipr[IPRA] &= ~((15)<<8);
+		SHREG_IPRA = ipr[IPRA];
+#else
 		SHREG_IPRA &= ~((15)<<8);
+#endif
 		break;
 	case SCI_IRQ:
+#ifdef SH7709A_BROKEN_IPR
+		ipr[IPRB] &= ~((15)<<4);
+		SHREG_IPRB = ipr[IPRB];
+#else
 		SHREG_IPRB &= ~((15)<<4);
+#endif
 		break;
 #if defined(SH7709) || defined(SH7709A) || defined(SH7729)
 	case SCIF_IRQ:
+#ifdef SH7709A_BROKEN_IPR
+		ipr[IPRE] &= ~((15)<<4);
+		SHREG_IPRE = ipr[IPRE];
+#else
 		SHREG_IPRE &= ~((15)<<4);
+#endif
 		break;
 #endif
 #if 0
@@ -545,14 +572,29 @@ unmask_irq(irq)
 
 	switch (irq) {
 	case TMU1_IRQ:
+#ifdef SH7709A_BROKEN_IPR
+		ipr[ IPRA ] |= ((15 - irq)<<8);
+		SHREG_IPRA = ipr[ IPRA ];
+#else
 		SHREG_IPRA |= ((15 - irq)<<8);
+#endif
 		break;
 	case SCI_IRQ:
+#ifdef SH7709A_BROKEN_IPR
+		ipr[IPRB] |= ((15 - irq)<<4);
+		SHREG_IPRB = ipr[IPRB];
+#else
 		SHREG_IPRB |= ((15 - irq)<<4);
+#endif
 		break;
 #if defined(SH7709) || defined(SH7709A) || defined(SH7729)
 	case SCIF_IRQ:
+#ifdef SH7709A_BROKEN_IPR
+		ipr[ IPRE ] |= ((15 - irq)<<4);
+		SHREG_IPRE = ipr[ IPRE ];
+#else
 		SHREG_IPRE |= ((15 - irq)<<4);
+#endif
 		break;
 #endif
 #if 0