From: Martyn Welch <martyn.welch@ge.com>
Date: Fri, 7 Feb 2014 15:48:56 +0000 (+0000)
Subject: VME: Correct read/write alignment algorithm
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=c7677684ab70aff2f5f514f8827d315833bc6ac3;p=linux-edison.git

VME: Correct read/write alignment algorithm

commit f0342e66b397947ed8c3eef8c37b5ca2d5b1bb50 upstream.

In order to ensure the correct width cycles on the VME bus, the VME bridge
drivers implement an algorithm to utilise the largest possible width reads and
writes whilst maintaining natural alignment constraints. The algorithm
currently looks at the start address rather than the current read/write address
when determining whether a 16-bit width cycle is required to get to 32-bit
alignment.  This results in incorrect alignment,

Reported-by: Jim Strouth <james.strouth@ge.com>
Tested-by: Jim Strouth <james.strouth@ge.com>
Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/vme/bridges/vme_ca91cx42.c b/drivers/vme/bridges/vme_ca91cx42.c
index 64bfea31442..8ca1030675a 100644
--- a/drivers/vme/bridges/vme_ca91cx42.c
+++ b/drivers/vme/bridges/vme_ca91cx42.c
@@ -880,7 +880,7 @@ static ssize_t ca91cx42_master_read(struct vme_master_resource *image,
 		if (done == count)
 			goto out;
 	}
-	if ((uintptr_t)addr & 0x2) {
+	if ((uintptr_t)(addr + done) & 0x2) {
 		if ((count - done) < 2) {
 			*(u8 *)(buf + done) = ioread8(addr + done);
 			done += 1;
@@ -934,7 +934,7 @@ static ssize_t ca91cx42_master_write(struct vme_master_resource *image,
 		if (done == count)
 			goto out;
 	}
-	if ((uintptr_t)addr & 0x2) {
+	if ((uintptr_t)(addr + done) & 0x2) {
 		if ((count - done) < 2) {
 			iowrite8(*(u8 *)(buf + done), addr + done);
 			done += 1;
diff --git a/drivers/vme/bridges/vme_tsi148.c b/drivers/vme/bridges/vme_tsi148.c
index 9c1aa4dc39c..63424060b04 100644
--- a/drivers/vme/bridges/vme_tsi148.c
+++ b/drivers/vme/bridges/vme_tsi148.c
@@ -1283,7 +1283,7 @@ static ssize_t tsi148_master_read(struct vme_master_resource *image, void *buf,
 		if (done == count)
 			goto out;
 	}
-	if ((uintptr_t)addr & 0x2) {
+	if ((uintptr_t)(addr + done) & 0x2) {
 		if ((count - done) < 2) {
 			*(u8 *)(buf + done) = ioread8(addr + done);
 			done += 1;
@@ -1365,7 +1365,7 @@ static ssize_t tsi148_master_write(struct vme_master_resource *image, void *buf,
 		if (done == count)
 			goto out;
 	}
-	if ((uintptr_t)addr & 0x2) {
+	if ((uintptr_t)(addr + done) & 0x2) {
 		if ((count - done) < 2) {
 			iowrite8(*(u8 *)(buf + done), addr + done);
 			done += 1;