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 64bfea3144293cb5b125a3cd1d6a57008cdf383d..8ca1030675a6fd2d21c6cb415538b12e3553a850 100644 (file)
--- 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 9c1aa4dc39c9051e95c9e1407d9ec335735bb1d8..63424060b04fc0fe7cae5b064614d5f9ed4a0023 100644 (file)
--- 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;