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| author |  Damien Le Moal <dlemoal@kernel.org>
| 2023-05-11 03:13:42 +0200 |
|---|---|---|
| committer |  Martin K. Petersen <martin.petersen@oracle.com>
| 2023-05-22 17:05:19 -0400 |
| commit | 1b22cfb14142aba7742d307c4f8d7006f919308c (patch) | |
| tree | 27f10d331c3e090a7e9903cd7c16663eaed9d4c7 /Documentation/ABI | |
| parent | scsi: core: Detect support for command duration limits (diff) | |
| download | linux-1b22cfb14142aba7742d307c4f8d7006f919308c.tar.gz linux-1b22cfb14142aba7742d307c4f8d7006f919308c.tar.bz2 linux-1b22cfb14142aba7742d307c4f8d7006f919308c.zip | |
scsi: core: Allow enabling and disabling command duration limits
Add the sysfs scsi_device attribute cdl_enable to allow a user to enable or
disable a device command duration limits feature. CDL is disabled by
default. This feature must be explicitly enabled by a user by setting the
cdl_enable attribute to 1.
The new function scsi_cdl_enable() does not do anything beside setting the
cdl_enable field of struct scsi_device in the case of a (real) SCSI device
(e.g. a SAS HDD). For ATA devices, the command duration limits feature
needs to be enabled/disabled using the ATA feature sub-page of the control
mode page. To do so, the scsi_cdl_enable() function checks if this mode
page is supported using scsi_mode_sense(). If it is, scsi_mode_select() is
used to enable and disable CDL.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-10-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-device | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device index ffc3358cba57..2d543cfa4079 100644 --- a/Documentation/ABI/testing/sysfs-block-device +++ b/Documentation/ABI/testing/sysfs-block-device @@ -104,3 +104,16 @@ Contact: linux-scsi@vger.kernel.org Description: (RO) Indicates if the device supports the command duration limits feature found in some ATA and SCSI devices. + + +What: /sys/block/*/device/cdl_enable +Date: May, 2023 +KernelVersion: v6.5 +Contact: linux-scsi@vger.kernel.org +Description: + (RW) For a device supporting the command duration limits + feature, write to the file to turn on or off the feature. + By default this feature is turned off. + Writing "1" to this file enables the use of command duration + limits for read and write commands in the kernel and turns on + the feature on the device. Writing "0" disables the feature. |