From 241ce89e8cb4067fc700468a4d658ae2215ec273 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B8ren=20Schmidt?= <sos@FreeBSD.org>
Date: Thu, 9 Dec 2004 07:31:06 +0000
Subject: [PATCH] Compensate for off by one bugs in disk firmware for 48BIT
 addressing cutover.

---
 sys/dev/ata/ata-all.h      | 2 ++
 sys/dev/ata/ata-chipset.c  | 2 +-
 sys/dev/ata/ata-disk.c     | 2 +-
 sys/dev/ata/ata-lowlevel.c | 2 +-
 4 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/sys/dev/ata/ata-all.h b/sys/dev/ata/ata-all.h
index 28d36c88dce6..6a9d09904dc0 100644
--- a/sys/dev/ata/ata-all.h
+++ b/sys/dev/ata/ata-all.h
@@ -156,6 +156,8 @@
 #define ATA_OP_CONTINUES		0
 #define ATA_OP_FINISHED			1
 
+#define ATA_MAX_28BIT_LBA		268435455
+
 /* ATAPI request sense structure */
 struct atapi_sense {
     u_int8_t	error_code	:7;		/* current or deferred errors */
diff --git a/sys/dev/ata/ata-chipset.c b/sys/dev/ata/ata-chipset.c
index 6c20240b4350..09f871596f68 100644
--- a/sys/dev/ata/ata-chipset.c
+++ b/sys/dev/ata/ata-chipset.c
@@ -1815,7 +1815,7 @@ ata_promise_apkt(u_int8_t *bytep, struct ata_device *atadev, u_int8_t command,
     bytep[i++] = ATA_PDC_1B | ATA_PDC_WRITE_CTL;
     bytep[i++] = ATA_A_4BIT;
 
-    if ((lba > 268435455 || count > 256) && atadev->param &&
+    if ((lba >= ATA_MAX_28BIT_LBA || count > 256) && atadev->param &&
 	(atadev->param->support.command2 & ATA_SUPPORT_ADDRESS48)) {
 	atadev->channel->flags |= ATA_48BIT_ACTIVE;
 	if (command == ATA_READ_DMA)
diff --git a/sys/dev/ata/ata-disk.c b/sys/dev/ata/ata-disk.c
index ccba1de78024..eebde22c4657 100644
--- a/sys/dev/ata/ata-disk.c
+++ b/sys/dev/ata/ata-disk.c
@@ -114,7 +114,7 @@ ad_attach(struct ata_device *atadev)
 
     /* use the 48bit LBA size if valid */
     if ((atadev->param->support.command2 & ATA_SUPPORT_ADDRESS48) &&
-	lbasize48 > 268435455)
+	lbasize48 > ATA_MAX_28BIT_LBA)
 	adp->total_secs = lbasize48;
 
     /* setup the function ptrs */
diff --git a/sys/dev/ata/ata-lowlevel.c b/sys/dev/ata/ata-lowlevel.c
index 3bc4c48f81d0..2a08bd0b42e5 100644
--- a/sys/dev/ata/ata-lowlevel.c
+++ b/sys/dev/ata/ata-lowlevel.c
@@ -701,7 +701,7 @@ ata_generic_command(struct ata_device *atadev, u_int8_t command,
     ATA_IDX_OUTB(atadev->channel, ATA_ALTSTAT, ATA_A_4BIT);
 
     /* only use 48bit addressing if needed (avoid bugs and overhead) */
-    if ((lba > 268435455 || count > 256) && atadev->param && 
+    if ((lba >= ATA_MAX_28BIT_LBA || count > 256) && atadev->param && 
 	atadev->param->support.command2 & ATA_SUPPORT_ADDRESS48) {
 
 	/* translate command into 48bit version */