path: root/Documentation/scsi
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authorChristoph Hellwig <hch@lst.de>2014-11-03 20:15:14 +0100
committerChristoph Hellwig <hch@lst.de>2014-11-12 11:19:43 +0100
commitc8b09f6fb67df7fc1b51ced1037fa9b677428149 (patch)
tree87527c3e17a7539c0ffa9f64fbd85ec2ad3dabf1 /Documentation/scsi
parent2ecb204d07ac8debe3893c362415919bc78bebd6 (diff)
scsi: don't set tagging state from scsi_adjust_queue_depth
Remove the tagged argument from scsi_adjust_queue_depth, and just let it handle the queue depth. For most drivers those two are fairly separate, given that most modern drivers don't care about the SCSI "tagged" status of a command at all, and many old drivers allow queuing of multiple untagged commands in the driver. Instead we start out with the ->simple_tags flag set before calling ->slave_configure, which is how all drivers actually looking at ->simple_tags except for one worke anyway. The one other case looks broken, but I've kept the behavior as-is for now. Except for that we only change ->simple_tags from the ->change_queue_type, and when rejecting a tag message in a single driver, so keeping this churn out of scsi_adjust_queue_depth is a clear win. Now that the usage of scsi_adjust_queue_depth is more obvious we can also remove all the trivial instances in ->slave_alloc or ->slave_configure that just set it to the cmd_per_lun default. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/scsi')
1 files changed, 4 insertions, 8 deletions
diff --git a/Documentation/scsi/scsi_mid_low_api.txt b/Documentation/scsi/scsi_mid_low_api.txt
index a67194209581..bee7d86b9dcc 100644
--- a/Documentation/scsi/scsi_mid_low_api.txt
+++ b/Documentation/scsi/scsi_mid_low_api.txt
@@ -271,9 +271,9 @@ init_this_scsi_driver() ----+
slave_destroy() ***
-The mid level invokes scsi_adjust_queue_depth() with tagged queuing off and
-"cmd_per_lun" for that host as the queue length. These settings can be
-overridden by a slave_configure() supplied by the LLD.
+The mid level invokes scsi_adjust_queue_depth() with "cmd_per_lun" for that
+host as the queue length. These settings can be overridden by a
+slave_configure() supplied by the LLD.
*** For scsi devices that the mid level tries to scan but do not
respond, a slave_alloc(), slave_destroy() pair is called.
@@ -438,9 +438,6 @@ int scsi_add_host(struct Scsi_Host *shost, struct device * dev)
* scsi_adjust_queue_depth - allow LLD to change queue depth on a SCSI device
* @sdev: pointer to SCSI device to change queue depth on
- * @tagged: 0 - no tagged queuing
- * MSG_SIMPLE_TAG - simple tagged queuing
- * MSG_ORDERED_TAG - ordered tagged queuing
* @tags Number of tags allowed if tagged queuing enabled,
* or number of commands the LLD can queue up
* in non-tagged mode (as per cmd_per_lun).
@@ -456,8 +453,7 @@ int scsi_add_host(struct Scsi_Host *shost, struct device * dev)
* Defined in: drivers/scsi/scsi.c [see source code for more notes]
-void scsi_adjust_queue_depth(struct scsi_device * sdev, int tagged,
- int tags)
+void scsi_adjust_queue_depth(struct scsi_device *sdev, int tags)

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