[SCSI] aacraid: resolve compiler warnings using ptrdiff_t

Unsigned long is not always the same size as a pointer, namely on 32 bit
systems with 64 bit address space. Ptrdiff_t is the same size as a
pointer in all configurations. By using ptrdiff_t we can mitigate the
warning messages on these configurations. There should be no side
effects of this patch.

Signed-off-by: Mark Salyzyn <aacraid@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index ae34768987a4..33682ce96a5d 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -5,7 +5,7 @@
  * based on the old aacraid driver that is..
  * Adaptec aacraid device driver for Linux.
  *
- * Copyright (c) 2000 Adaptec, Inc. (aacraid@adaptec.com)
+ * Copyright (c) 2000-2007 Adaptec, Inc. (aacraid@adaptec.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -110,7 +110,7 @@ static int aac_alloc_comm(struct aac_dev *dev, void **commaddr, unsigned long co
         /*
          *      Align the beginning of Headers to commalign
          */
-        align = (commalign - ((unsigned long)(base) & (commalign - 1)));
+        align = (commalign - ((ptrdiff_t)(base) & (commalign - 1)));
         base = base + align;
         phys = phys + align;
         /*