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| author | Christoph Hellwig <hch@lst.de> | 2014-11-03 14:09:02 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-11-12 11:19:43 +0100 |
| commit | 2ecb204d07ac8debe3893c362415919bc78bebd6 (patch) | |
| tree | eef99b324201b21de358dffdab8bfc0453358d5f /Documentation/scsi | |
| parent | scsi: remove use_blk_tcq Scsi_Host field (diff) | |
| download | linux-2ecb204d07ac8debe3893c362415919bc78bebd6.tar.xz linux-2ecb204d07ac8debe3893c362415919bc78bebd6.zip | |
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.txt | 38 |
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 |