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author | Christoph Hellwig <hch@lst.de> | 2014-10-02 14:39:55 +0200 |
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committer | Christoph Hellwig <hch@lst.de> | 2014-11-12 11:19:39 +0100 |
commit | a62182f338b39a22035531c6afc0a8d2928b1df2 (patch) | |
tree | 57ca6cea82a09d2655daf5c161024c5015373646 /drivers/scsi/scsi.c | |
parent | 1d5203284d8acbdfdf9b478d434450b34f338f28 (diff) | |
download | linux-a62182f338b39a22035531c6afc0a8d2928b1df2.tar.gz linux-a62182f338b39a22035531c6afc0a8d2928b1df2.tar.bz2 linux-a62182f338b39a22035531c6afc0a8d2928b1df2.zip |
scsi: provide a generic change_queue_type method
Most drivers use exactly the same implementation, so provide it as a
library function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Diffstat (limited to 'drivers/scsi/scsi.c')
-rw-r--r-- | drivers/scsi/scsi.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index bc52bbd97381..9baeff03dd9b 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -867,6 +867,26 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth) EXPORT_SYMBOL(scsi_track_queue_full); /** + * scsi_change_queue_type() - Change a device's queue type + * @sdev: The SCSI device whose queue depth is to change + * @tag_type: Identifier for queue type + */ +int scsi_change_queue_type(struct scsi_device *sdev, int tag_type) +{ + if (sdev->tagged_supported) { + scsi_set_tag_type(sdev, tag_type); + if (tag_type) + scsi_activate_tcq(sdev, sdev->queue_depth); + else + scsi_deactivate_tcq(sdev, sdev->queue_depth); + } else + tag_type = 0; + + return tag_type; +} +EXPORT_SYMBOL(scsi_change_queue_type); + +/** * scsi_vpd_inquiry - Request a device provide us with a VPD page * @sdev: The device to ask * @buffer: Where to put the result |