VME: Correct read/write alignment algorithm

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>
Cc: stable <stable@vger.kernel.org>
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 a06edbf..1b5d48c 100644 (file)
--- a/drivers/vme/bridges/vme_ca91cx42.c
+++ b/drivers/vme/bridges/vme_ca91cx42.c
@@ -884,7 +884,7 @@ 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;
@@ -938,7 +938,7 @@ 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 16830d8..9911cd5 100644 (file)
--- a/drivers/vme/bridges/vme_tsi148.c
+++ b/drivers/vme/bridges/vme_tsi148.c
@@ -1289,7 +1289,7 @@ 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;
@@ -1371,7 +1371,7 @@ 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;