Commit 482eb689 authored Jan 01, 2008 by Pete Wyckoff Committed by Jens Axboe Jan 28, 2008

block: allow queue dma_alignment of zero



Let queue_dma_alignment return 0 if it was specifically set to 0.
This permits devices with no particular alignment restrictions to
use arbitrary user space buffers without copying.

Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

parent 6da127ad

include/linux/blkdev.h

+1 −6

Original line number	Diff line number	Diff line
		@@ -836,12 +836,7 @@ static inline int bdev_hardsect_size(struct block_device *bdev)

		static inline int queue_dma_alignment(struct request_queue *q)
		{
		int retval = 511;

		if (q && q->dma_alignment)
		retval = q->dma_alignment;

		return retval;
		return q ? q->dma_alignment : 511;
		}

		/* assumes size > 256 */