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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2010-08-10 18:03:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-11 08:59:21 -0700
commitd80e0d96a328cc864a1cb359f545a6ed0c61812d (patch)
tree805689907e865c14943b7b77b7b1d64ca8044e01 /arch
parent7896bfa451b209f73bc8ec14721dcc2c5329a0a9 (diff)
downloadlinux-d80e0d96a328cc864a1cb359f545a6ed0c61812d.tar.gz
scsi: 53c700: remove dma_is_consistent usage
This driver is the only user of dma_is_consistent().  We plan to remove this
API.

The driver uses the API in the following way:

BUG_ON(!dma_is_consistent(hostdata->dev, pScript) && L1_CACHE_BYTES < dma_get_cache_alignment());

The above code tries to see if L1_CACHE_BYTES is greater than
dma_get_cache_alignment() on sysmtes that can not allocate coherent memory
(some old systems can't).

James Bottomley exmplained that this is necesary because the driver packs the
set of mailboxes into a single coherent area and separates the different
usages by a L1 cache stride.  So it's fatal if the dma

He also pointed out that we can kill this checking because we don't hit this
BUG_ON on all architectures that actually use the driver.

(akpm: stolen from the scsi tree because
dma-mapping-remove-dma_is_consistent-api.patch needs it)

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions