bounce: call flush_dcache_page() after bounce_copy_vec()
authorGary King <gking@nvidia.com>
Thu, 9 Sep 2010 23:38:05 +0000 (16:38 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 10 Sep 2010 01:57:25 +0000 (18:57 -0700)
commitac8456d6f9a3011c824176bd6084d39e5f70a382
tree8973f7b5f9993d34d0301380972475dca2410afd
parent47016434257b90445113eed1c5b8b57eb2d35330
bounce: call flush_dcache_page() after bounce_copy_vec()

I have been seeing problems on Tegra 2 (ARMv7 SMP) systems with HIGHMEM
enabled on 2.6.35 (plus some patches targetted at 2.6.36 to perform cache
maintenance lazily), and the root cause appears to be that the mm bouncing
code is calling flush_dcache_page before it copies the bounce buffer into
the bio.

The bounced page needs to be flushed after data is copied into it, to
ensure that architecture implementations can synchronize instruction and
data caches if necessary.

Signed-off-by: Gary King <gking@nvidia.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/bounce.c