Re: [PATCH] libata: update documentation for sysfs interfaces

[Tejun Heo]

On Tue, Feb 13, 2018 at 01:48:16PM +0530, Aishwarya Pant wrote:
> Dcoumentation has been added by parsing through git commit history and
> reading code. This might be useful for scripting and tracking changes in
> the ABI.
> 
> I do not have complete descriptions for the following 3 attributes; they
> have been annotated with the comment [to be documented] -
> 
>   /sys/class/scsi_host/hostX/ahci_port_cmd
>   /sys/class/scsi_host/hostX/ahci_host_caps
>   /sys/class/scsi_host/hostX/ahci_host_cap2
> 
> Signed-off-by: Aishwarya Pant 

Applied to libata/for-4.16-fixes.

Thanks.

-- 
tejun

Re: [PATCH] libata: update documentation for sysfs interfaces

[Tejun Heo]

On Tue, Feb 13, 2018 at 01:48:16PM +0530, Aishwarya Pant wrote:
> Dcoumentation has been added by parsing through git commit history and
> reading code. This might be useful for scripting and tracking changes in
> the ABI.
> 
> I do not have complete descriptions for the following 3 attributes; they
> have been annotated with the comment [to be documented] -
> 
>   /sys/class/scsi_host/hostX/ahci_port_cmd
>   /sys/class/scsi_host/hostX/ahci_host_caps
>   /sys/class/scsi_host/hostX/ahci_host_cap2
> 
> Signed-off-by: Aishwarya Pant 

Applied to libata/for-4.16-fixes.

Thanks.

-- 
tejun

[PATCH] libata: update documentation for sysfs interfaces

[Aishwarya Pant]

Dcoumentation has been added by parsing through git commit history and
reading code. This might be useful for scripting and tracking changes in
the ABI.

I do not have complete descriptions for the following 3 attributes; they
have been annotated with the comment [to be documented] -

/sys/class/scsi_host/hostX/ahci_port_cmd
/sys/class/scsi_host/hostX/ahci_host_caps
/sys/class/scsi_host/hostX/ahci_host_cap2

Signed-off-by: Aishwarya Pant 
---
 Documentation/ABI/testing/sysfs-block-device| 58 
 Documentation/ABI/testing/sysfs-class-scsi_host | 89 +
 2 files changed, 147 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-block-device

diff --git a/Documentation/ABI/testing/sysfs-block-device 
b/Documentation/ABI/testing/sysfs-block-device
new file mode 100644
index ..82ef6eab042d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-block-device
@@ -0,0 +1,58 @@
+What:  /sys/block/*/device/sw_activity
+Date:  Jun, 2008
+KernelVersion: v2.6.27
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) Used by drivers which support software controlled activity
+   LEDs.
+
+   It has the following valid values:
+
+   0   OFF - the LED is not activated on activity
+   1   BLINK_ON - the LED blinks on every 10ms when activity is
+   detected.
+   2   BLINK_OFF - the LED is on when idle, and blinks off
+   every 10ms when activity is detected.
+
+   Note that the user must turn sw_activity OFF it they wish to
+   control the activity LED via the em_message file.
+
+
+What:  /sys/block/*/device/unload_heads
+Date:  Sep, 2008
+KernelVersion: v2.6.28
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) Hard disk shock protection
+
+   Writing an integer value to this file will take the heads of the
+   respective drive off the platter and block all I/O operations
+   for the specified number of milliseconds.
+
+   - If the device does not support the unload heads feature,
+ access is denied with -EOPNOTSUPP.
+   - The maximal value accepted for a timeout is 3
+ milliseconds.
+   - A previously set timeout can be cancelled and disk can resume
+ normal operation immediately by specifying a timeout of 0.
+   - Some hard drives only comply with an earlier version of the
+ ATA standard, but support the unload feature nonetheless.
+ There is no safe way Linux can detect these devices, so this
+ is not enabled by default. If it is known that your device
+ does support the unload feature, then you can tell the kernel
+ to enable it by writing -1. It can be disabled again by
+ writing -2.
+   - Values below -2 are rejected with -EINVAL
+
+   For more information, see
+   Documentation/laptops/disk-shock-protection.txt
+
+
+What:  /sys/block/*/device/ncq_prio_enable
+Date:  Oct, 2016
+KernelVersion: v4.10
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) Write to the file to turn on or off the SATA ncq (native
+   command queueing) support. By default this feature is turned
+   off.
diff --git a/Documentation/ABI/testing/sysfs-class-scsi_host 
b/Documentation/ABI/testing/sysfs-class-scsi_host
index 0eb255e7db12..bafc59fd7b69 100644
--- a/Documentation/ABI/testing/sysfs-class-scsi_host
+++ b/Documentation/ABI/testing/sysfs-class-scsi_host
@@ -27,3 +27,92 @@ Description: This file contains the current status of the 
"SSD Smart Path"
the direct i/o path to physical devices.  This setting is
controller wide, affecting all configured logical drives on the
controller.  This file is readable and writable.
+
+What:  /sys/class/scsi_host/hostX/link_power_management_policy
+Date:  Oct, 2007
+KernelVersion: v2.6.24
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) This parameter allows the user to read and set the link
+   (interface) power management.
+
+   There are four possible options:
+
+   min_power: Tell the controller to try to make the link use the
+   least possible power when possible. This may sacrifice some
+   performance due to increased latency when coming out of lower
+   power states.
+
+   max_performance: Generally, this means no power management.
+   Tell the controller to have performance be a priority over power
+   management.
+
+   medium_power: Tell the 

[PATCH] libata: update documentation for sysfs interfaces

[Aishwarya Pant]

Dcoumentation has been added by parsing through git commit history and
reading code. This might be useful for scripting and tracking changes in
the ABI.

I do not have complete descriptions for the following 3 attributes; they
have been annotated with the comment [to be documented] -

/sys/class/scsi_host/hostX/ahci_port_cmd
/sys/class/scsi_host/hostX/ahci_host_caps
/sys/class/scsi_host/hostX/ahci_host_cap2

Signed-off-by: Aishwarya Pant 
---
 Documentation/ABI/testing/sysfs-block-device| 58 
 Documentation/ABI/testing/sysfs-class-scsi_host | 89 +
 2 files changed, 147 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-block-device

diff --git a/Documentation/ABI/testing/sysfs-block-device 
b/Documentation/ABI/testing/sysfs-block-device
new file mode 100644
index ..82ef6eab042d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-block-device
@@ -0,0 +1,58 @@
+What:  /sys/block/*/device/sw_activity
+Date:  Jun, 2008
+KernelVersion: v2.6.27
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) Used by drivers which support software controlled activity
+   LEDs.
+
+   It has the following valid values:
+
+   0   OFF - the LED is not activated on activity
+   1   BLINK_ON - the LED blinks on every 10ms when activity is
+   detected.
+   2   BLINK_OFF - the LED is on when idle, and blinks off
+   every 10ms when activity is detected.
+
+   Note that the user must turn sw_activity OFF it they wish to
+   control the activity LED via the em_message file.
+
+
+What:  /sys/block/*/device/unload_heads
+Date:  Sep, 2008
+KernelVersion: v2.6.28
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) Hard disk shock protection
+
+   Writing an integer value to this file will take the heads of the
+   respective drive off the platter and block all I/O operations
+   for the specified number of milliseconds.
+
+   - If the device does not support the unload heads feature,
+ access is denied with -EOPNOTSUPP.
+   - The maximal value accepted for a timeout is 3
+ milliseconds.
+   - A previously set timeout can be cancelled and disk can resume
+ normal operation immediately by specifying a timeout of 0.
+   - Some hard drives only comply with an earlier version of the
+ ATA standard, but support the unload feature nonetheless.
+ There is no safe way Linux can detect these devices, so this
+ is not enabled by default. If it is known that your device
+ does support the unload feature, then you can tell the kernel
+ to enable it by writing -1. It can be disabled again by
+ writing -2.
+   - Values below -2 are rejected with -EINVAL
+
+   For more information, see
+   Documentation/laptops/disk-shock-protection.txt
+
+
+What:  /sys/block/*/device/ncq_prio_enable
+Date:  Oct, 2016
+KernelVersion: v4.10
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) Write to the file to turn on or off the SATA ncq (native
+   command queueing) support. By default this feature is turned
+   off.
diff --git a/Documentation/ABI/testing/sysfs-class-scsi_host 
b/Documentation/ABI/testing/sysfs-class-scsi_host
index 0eb255e7db12..bafc59fd7b69 100644
--- a/Documentation/ABI/testing/sysfs-class-scsi_host
+++ b/Documentation/ABI/testing/sysfs-class-scsi_host
@@ -27,3 +27,92 @@ Description: This file contains the current status of the 
"SSD Smart Path"
the direct i/o path to physical devices.  This setting is
controller wide, affecting all configured logical drives on the
controller.  This file is readable and writable.
+
+What:  /sys/class/scsi_host/hostX/link_power_management_policy
+Date:  Oct, 2007
+KernelVersion: v2.6.24
+Contact:   linux-...@vger.kernel.org
+Description:
+   (RW) This parameter allows the user to read and set the link
+   (interface) power management.
+
+   There are four possible options:
+
+   min_power: Tell the controller to try to make the link use the
+   least possible power when possible. This may sacrifice some
+   performance due to increased latency when coming out of lower
+   power states.
+
+   max_performance: Generally, this means no power management.
+   Tell the controller to have performance be a priority over power
+   management.
+
+   medium_power: Tell the controller to enter a