[SCSI] add use_sg_chaining option to scsi_host_template

This option is true if a low-level driver can support sg
chaining. This will be removed eventually when all the drivers are
converted to support sg chaining. q->max_phys_segments is set to
SCSI_MAX_SG_SEGMENTS if false.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
FUJITA Tomonori
2007-10-16 11:24:32 +02:00
committed by Jens Axboe
parent c0dcffd71d
commit 9cb83c7529
39 changed files with 58 additions and 3 deletions

View File

@@ -1645,7 +1645,10 @@ struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
* converted, so better keep it safe.
*/
#ifdef ARCH_HAS_SG_CHAIN
blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS);
if (shost->use_sg_chaining)
blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS);
else
blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS);
#else
blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS);
#endif