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authorChristoph Hellwig <hch@lst.de>2014-11-03 14:09:02 +0100
committerChristoph Hellwig <hch@lst.de>2014-11-12 11:19:43 +0100
commit2ecb204d07ac8debe3893c362415919bc78bebd6 (patch)
treeeef99b324201b21de358dffdab8bfc0453358d5f /Documentation/scsi
parente2eddf4d530df745019fded0fedfb78f6d3e33ca (diff)
scsi: always assign block layer tags if enabled
Allow a driver to ask for block layer tags by setting .use_blk_tags in the host template, in which case it will always see a valid value in request->tag, similar to the behavior when using blk-mq. This means even SCSI "untagged" commands will now have a tag, which is especially useful when using a host-wide tag map. Signed-off-by: Christoph Hellwig <hch@lst.de> 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 'Documentation/scsi')
-rw-r--r--Documentation/scsi/scsi_mid_low_api.txt38
1 files changed, 1 insertions, 37 deletions
diff --git a/Documentation/scsi/scsi_mid_low_api.txt b/Documentation/scsi/scsi_mid_low_api.txt
index d6a9bdeee7f2..a67194209581 100644
--- a/Documentation/scsi/scsi_mid_low_api.txt
+++ b/Documentation/scsi/scsi_mid_low_api.txt
@@ -366,13 +366,11 @@ is initialized. The functions below are listed alphabetically and their
names all start with "scsi_".
Summary:
- scsi_activate_tcq - turn on tag command queueing
scsi_add_device - creates new scsi device (lu) instance
scsi_add_host - perform sysfs registration and set up transport class
scsi_adjust_queue_depth - change the queue depth on a SCSI device
scsi_bios_ptable - return copy of block device's partition table
scsi_block_requests - prevent further commands being queued to given host
- scsi_deactivate_tcq - turn off tag command queueing
scsi_host_alloc - return a new scsi_host instance whose refcount==1
scsi_host_get - increments Scsi_Host instance's refcount
scsi_host_put - decrements Scsi_Host instance's refcount (free if 0)
@@ -390,24 +388,6 @@ Summary:
Details:
/**
- * scsi_activate_tcq - turn on tag command queueing ("ordered" task attribute)
- * @sdev: device to turn on TCQ for
- * @depth: queue depth
- *
- * Returns nothing
- *
- * Might block: no
- *
- * Notes: Eventually, it is hoped depth would be the maximum depth
- * the device could cope with and the real queue depth
- * would be adjustable from 0 to depth.
- *
- * Defined (inline) in: include/scsi/scsi_tcq.h
- **/
-void scsi_activate_tcq(struct scsi_device *sdev, int depth)
-
-
-/**
* scsi_add_device - creates new scsi device (lu) instance
* @shost: pointer to scsi host instance
* @channel: channel number (rarely other than 0)
@@ -471,9 +451,7 @@ int scsi_add_host(struct Scsi_Host *shost, struct device * dev)
*
* Notes: Can be invoked any time on a SCSI device controlled by this
* LLD. [Specifically during and after slave_configure() and prior to
- * slave_destroy().] Can safely be invoked from interrupt code. Actual
- * queue depth change may be delayed until the next command is being
- * processed. See also scsi_activate_tcq() and scsi_deactivate_tcq().
+ * slave_destroy().] Can safely be invoked from interrupt code.
*
* Defined in: drivers/scsi/scsi.c [see source code for more notes]
*
@@ -515,20 +493,6 @@ void scsi_block_requests(struct Scsi_Host * shost)
/**
- * scsi_deactivate_tcq - turn off tag command queueing
- * @sdev: device to turn off TCQ for
- * @depth: queue depth (stored in sdev)
- *
- * Returns nothing
- *
- * Might block: no
- *
- * Defined (inline) in: include/scsi/scsi_tcq.h
- **/
-void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
-
-
-/**
* scsi_host_alloc - create a scsi host adapter instance and perform basic
* initialization.
* @sht: pointer to scsi host template

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