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 f8448573d030b3d84dcd12d5c746c4156394fdae..0b2fefbfcd102cb7901941565dcef1e268f0bbe5 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 9cf88337e4e9a50423a140e940c71c5a25fe3e9f..7db4e6395e23bd933bed0357c56d6dce9848e02a 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;