[ARM] Orion NAND: Make asm volatile avoid GCC pushing ldrd out of the loop

GCC 4.3.3 and 4.4.1 happily moves the dword load instruction out of the
loop in orion_nand_read_buf. This patch makes the instruction volatile
to avoid the issue. I've discussed this at gcc-help, refer to the thread
at

  http://gcc.gnu.org/ml/gcc-help/2009-08/msg00187.html

The early clobber is added to avoid the destination registers and the
source register overlapping.

Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
Signed-off-by: Nicolas Pitre <nico@marvell.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c
index 7ad972229db4..0d9d4bc9c762 100644
--- a/drivers/mtd/nand/orion_nand.c
+++ b/drivers/mtd/nand/orion_nand.c
@@ -61,7 +61,7 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
         buf64 = (uint64_t *)buf;
         while (i < len/8) {
                 uint64_t x;
-                asm ("ldrd\t%0, [%1]" : "=r" (x) : "r" (io_base));
+                asm volatile ("ldrd\t%0, [%1]" : "=&r" (x) : "r" (io_base));
                 buf64[i++] = x;
         }
         i *= 8;