Loading Documentation/ABI/testing/sysfs-block +14 −0 Original line number Diff line number Diff line Loading @@ -128,3 +128,17 @@ Description: preferred request size for workloads where sustained throughput is desired. If no optimal I/O size is reported this file contains 0. What: /sys/block/<disk>/queue/nomerges Date: January 2010 Contact: Description: Standard I/O elevator operations include attempts to merge contiguous I/Os. For known random I/O loads these attempts will always fail and result in extra cycles being spent in the kernel. This allows one to turn off this behavior on one of two ways: When set to 1, complex merge checks are disabled, but the simple one-shot merges with the previous I/O request are enabled. When set to 2, all merge tries are disabled. The default value is 0 - which enables all types of merge tries. Documentation/ABI/testing/sysfs-devices-power 0 → 100644 +79 −0 Original line number Diff line number Diff line What: /sys/devices/.../power/ Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../power directory contains attributes allowing the user space to check and modify some power management related properties of given device. What: /sys/devices/.../power/wakeup Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../power/wakeup attribute allows the user space to check if the device is enabled to wake up the system from sleep states, such as the memory sleep state (suspend to RAM) and hibernation (suspend to disk), and to enable or disable it to do that as desired. Some devices support "wakeup" events, which are hardware signals used to activate the system from a sleep state. Such devices have one of the following two values for the sysfs power/wakeup file: + "enabled\n" to issue the events; + "disabled\n" not to do so; In that cases the user space can change the setting represented by the contents of this file by writing either "enabled", or "disabled" to it. For the devices that are not capable of generating system wakeup events this file contains "\n". In that cases the user space cannot modify the contents of this file and the device cannot be enabled to wake up the system. What: /sys/devices/.../power/control Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../power/control attribute allows the user space to control the run-time power management of the device. All devices have one of the following two values for the power/control file: + "auto\n" to allow the device to be power managed at run time; + "on\n" to prevent the device from being power managed; The default for all devices is "auto", which means that they may be subject to automatic power management, depending on their drivers. Changing this attribute to "on" prevents the driver from power managing the device at run time. Doing that while the device is suspended causes it to be woken up. What: /sys/devices/.../power/async Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../async attribute allows the user space to enable or diasble the device's suspend and resume callbacks to be executed asynchronously (ie. in separate threads, in parallel with the main suspend/resume thread) during system-wide power transitions (eg. suspend to RAM, hibernation). All devices have one of the following two values for the power/async file: + "enabled\n" to permit the asynchronous suspend/resume; + "disabled\n" to forbid it; The value of this attribute may be changed by writing either "enabled", or "disabled" to it. It generally is unsafe to permit the asynchronous suspend/resume of a device unless it is certain that all of the PM dependencies of the device are known to the PM core. However, for some devices this attribute is set to "enabled" by bus type code or device drivers and in that cases it should be safe to leave the default value. Documentation/ABI/testing/sysfs-power +13 −0 Original line number Diff line number Diff line Loading @@ -101,3 +101,16 @@ Description: CAUTION: Using it will cause your machine's real-time (CMOS) clock to be set to a random invalid time after a resume. What: /sys/power/pm_async Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/power/pm_async file controls the switch allowing the user space to enable or disable asynchronous suspend and resume of devices. If enabled, this feature will cause some device drivers' suspend and resume callbacks to be executed in parallel with each other and with the main suspend thread. It is enabled if this file contains "1", which is the default. It may be disabled by writing "0" to this file, in which case all devices will be suspended and resumed synchronously. Documentation/DocBook/v4l/io.xml +2 −1 Original line number Diff line number Diff line Loading @@ -589,7 +589,8 @@ number of a video input as in &v4l2-input; field <entry></entry> <entry>A place holder for future extensions and custom (driver defined) buffer types <constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry> <constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher. Applications should set this to 0.</entry> </row> </tbody> </tgroup> Loading Documentation/DocBook/v4l/vidioc-qbuf.xml +23 −17 Original line number Diff line number Diff line Loading @@ -54,12 +54,10 @@ to enqueue an empty (capturing) or filled (output) buffer in the driver's incoming queue. The semantics depend on the selected I/O method.</para> <para>To enqueue a <link linkend="mmap">memory mapped</link> buffer applications set the <structfield>type</structfield> field of a &v4l2-buffer; to the same buffer type as previously &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers; <structfield>type</structfield>, the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_MMAP</constant> and the <para>To enqueue a buffer applications set the <structfield>type</structfield> field of a &v4l2-buffer; to the same buffer type as was previously used with &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers; <structfield>type</structfield>. Applications must also set the <structfield>index</structfield> field. Valid index numbers range from zero to the number of buffers allocated with &VIDIOC-REQBUFS; (&v4l2-requestbuffers; <structfield>count</structfield>) minus one. The Loading @@ -70,8 +68,19 @@ intended for output (<structfield>type</structfield> is <constant>V4L2_BUF_TYPE_VBI_OUTPUT</constant>) applications must also initialize the <structfield>bytesused</structfield>, <structfield>field</structfield> and <structfield>timestamp</structfield> fields. See <xref linkend="buffer" /> for details. When <structfield>timestamp</structfield> fields, see <xref linkend="buffer" /> for details. Applications must also set <structfield>flags</structfield> to 0. If a driver supports capturing from specific video inputs and you want to specify a video input, then <structfield>flags</structfield> should be set to <constant>V4L2_BUF_FLAG_INPUT</constant> and the field <structfield>input</structfield> must be initialized to the desired input. The <structfield>reserved</structfield> field must be set to 0. </para> <para>To enqueue a <link linkend="mmap">memory mapped</link> buffer applications set the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_MMAP</constant>. When <constant>VIDIOC_QBUF</constant> is called with a pointer to this structure the driver sets the <constant>V4L2_BUF_FLAG_MAPPED</constant> and Loading @@ -81,14 +90,10 @@ structure the driver sets the &EINVAL;.</para> <para>To enqueue a <link linkend="userp">user pointer</link> buffer applications set the <structfield>type</structfield> field of a &v4l2-buffer; to the same buffer type as previously &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers; <structfield>type</structfield>, the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_USERPTR</constant> and the buffer applications set the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_USERPTR</constant>, the <structfield>m.userptr</structfield> field to the address of the buffer and <structfield>length</structfield> to its size. When the buffer is intended for output additional fields must be set as above. buffer and <structfield>length</structfield> to its size. When <constant>VIDIOC_QBUF</constant> is called with a pointer to this structure the driver sets the <constant>V4L2_BUF_FLAG_QUEUED</constant> flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and Loading @@ -96,13 +101,14 @@ flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and <structfield>flags</structfield> field, or it returns an error code. This ioctl locks the memory pages of the buffer in physical memory, they cannot be swapped out to disk. Buffers remain locked until dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl are dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is called, or until the device is closed.</para> <para>Applications call the <constant>VIDIOC_DQBUF</constant> ioctl to dequeue a filled (capturing) or displayed (output) buffer from the driver's outgoing queue. They just set the <structfield>type</structfield> and <structfield>memory</structfield> <structfield>type</structfield>, <structfield>memory</structfield> and <structfield>reserved</structfield> fields of a &v4l2-buffer; as above, when <constant>VIDIOC_DQBUF</constant> is called with a pointer to this structure the driver fills the remaining fields or returns an error code.</para> Loading Loading
Documentation/ABI/testing/sysfs-block +14 −0 Original line number Diff line number Diff line Loading @@ -128,3 +128,17 @@ Description: preferred request size for workloads where sustained throughput is desired. If no optimal I/O size is reported this file contains 0. What: /sys/block/<disk>/queue/nomerges Date: January 2010 Contact: Description: Standard I/O elevator operations include attempts to merge contiguous I/Os. For known random I/O loads these attempts will always fail and result in extra cycles being spent in the kernel. This allows one to turn off this behavior on one of two ways: When set to 1, complex merge checks are disabled, but the simple one-shot merges with the previous I/O request are enabled. When set to 2, all merge tries are disabled. The default value is 0 - which enables all types of merge tries.
Documentation/ABI/testing/sysfs-devices-power 0 → 100644 +79 −0 Original line number Diff line number Diff line What: /sys/devices/.../power/ Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../power directory contains attributes allowing the user space to check and modify some power management related properties of given device. What: /sys/devices/.../power/wakeup Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../power/wakeup attribute allows the user space to check if the device is enabled to wake up the system from sleep states, such as the memory sleep state (suspend to RAM) and hibernation (suspend to disk), and to enable or disable it to do that as desired. Some devices support "wakeup" events, which are hardware signals used to activate the system from a sleep state. Such devices have one of the following two values for the sysfs power/wakeup file: + "enabled\n" to issue the events; + "disabled\n" not to do so; In that cases the user space can change the setting represented by the contents of this file by writing either "enabled", or "disabled" to it. For the devices that are not capable of generating system wakeup events this file contains "\n". In that cases the user space cannot modify the contents of this file and the device cannot be enabled to wake up the system. What: /sys/devices/.../power/control Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../power/control attribute allows the user space to control the run-time power management of the device. All devices have one of the following two values for the power/control file: + "auto\n" to allow the device to be power managed at run time; + "on\n" to prevent the device from being power managed; The default for all devices is "auto", which means that they may be subject to automatic power management, depending on their drivers. Changing this attribute to "on" prevents the driver from power managing the device at run time. Doing that while the device is suspended causes it to be woken up. What: /sys/devices/.../power/async Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/devices/.../async attribute allows the user space to enable or diasble the device's suspend and resume callbacks to be executed asynchronously (ie. in separate threads, in parallel with the main suspend/resume thread) during system-wide power transitions (eg. suspend to RAM, hibernation). All devices have one of the following two values for the power/async file: + "enabled\n" to permit the asynchronous suspend/resume; + "disabled\n" to forbid it; The value of this attribute may be changed by writing either "enabled", or "disabled" to it. It generally is unsafe to permit the asynchronous suspend/resume of a device unless it is certain that all of the PM dependencies of the device are known to the PM core. However, for some devices this attribute is set to "enabled" by bus type code or device drivers and in that cases it should be safe to leave the default value.
Documentation/ABI/testing/sysfs-power +13 −0 Original line number Diff line number Diff line Loading @@ -101,3 +101,16 @@ Description: CAUTION: Using it will cause your machine's real-time (CMOS) clock to be set to a random invalid time after a resume. What: /sys/power/pm_async Date: January 2009 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/power/pm_async file controls the switch allowing the user space to enable or disable asynchronous suspend and resume of devices. If enabled, this feature will cause some device drivers' suspend and resume callbacks to be executed in parallel with each other and with the main suspend thread. It is enabled if this file contains "1", which is the default. It may be disabled by writing "0" to this file, in which case all devices will be suspended and resumed synchronously.
Documentation/DocBook/v4l/io.xml +2 −1 Original line number Diff line number Diff line Loading @@ -589,7 +589,8 @@ number of a video input as in &v4l2-input; field <entry></entry> <entry>A place holder for future extensions and custom (driver defined) buffer types <constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry> <constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher. Applications should set this to 0.</entry> </row> </tbody> </tgroup> Loading
Documentation/DocBook/v4l/vidioc-qbuf.xml +23 −17 Original line number Diff line number Diff line Loading @@ -54,12 +54,10 @@ to enqueue an empty (capturing) or filled (output) buffer in the driver's incoming queue. The semantics depend on the selected I/O method.</para> <para>To enqueue a <link linkend="mmap">memory mapped</link> buffer applications set the <structfield>type</structfield> field of a &v4l2-buffer; to the same buffer type as previously &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers; <structfield>type</structfield>, the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_MMAP</constant> and the <para>To enqueue a buffer applications set the <structfield>type</structfield> field of a &v4l2-buffer; to the same buffer type as was previously used with &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers; <structfield>type</structfield>. Applications must also set the <structfield>index</structfield> field. Valid index numbers range from zero to the number of buffers allocated with &VIDIOC-REQBUFS; (&v4l2-requestbuffers; <structfield>count</structfield>) minus one. The Loading @@ -70,8 +68,19 @@ intended for output (<structfield>type</structfield> is <constant>V4L2_BUF_TYPE_VBI_OUTPUT</constant>) applications must also initialize the <structfield>bytesused</structfield>, <structfield>field</structfield> and <structfield>timestamp</structfield> fields. See <xref linkend="buffer" /> for details. When <structfield>timestamp</structfield> fields, see <xref linkend="buffer" /> for details. Applications must also set <structfield>flags</structfield> to 0. If a driver supports capturing from specific video inputs and you want to specify a video input, then <structfield>flags</structfield> should be set to <constant>V4L2_BUF_FLAG_INPUT</constant> and the field <structfield>input</structfield> must be initialized to the desired input. The <structfield>reserved</structfield> field must be set to 0. </para> <para>To enqueue a <link linkend="mmap">memory mapped</link> buffer applications set the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_MMAP</constant>. When <constant>VIDIOC_QBUF</constant> is called with a pointer to this structure the driver sets the <constant>V4L2_BUF_FLAG_MAPPED</constant> and Loading @@ -81,14 +90,10 @@ structure the driver sets the &EINVAL;.</para> <para>To enqueue a <link linkend="userp">user pointer</link> buffer applications set the <structfield>type</structfield> field of a &v4l2-buffer; to the same buffer type as previously &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers; <structfield>type</structfield>, the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_USERPTR</constant> and the buffer applications set the <structfield>memory</structfield> field to <constant>V4L2_MEMORY_USERPTR</constant>, the <structfield>m.userptr</structfield> field to the address of the buffer and <structfield>length</structfield> to its size. When the buffer is intended for output additional fields must be set as above. buffer and <structfield>length</structfield> to its size. When <constant>VIDIOC_QBUF</constant> is called with a pointer to this structure the driver sets the <constant>V4L2_BUF_FLAG_QUEUED</constant> flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and Loading @@ -96,13 +101,14 @@ flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and <structfield>flags</structfield> field, or it returns an error code. This ioctl locks the memory pages of the buffer in physical memory, they cannot be swapped out to disk. Buffers remain locked until dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl are dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is called, or until the device is closed.</para> <para>Applications call the <constant>VIDIOC_DQBUF</constant> ioctl to dequeue a filled (capturing) or displayed (output) buffer from the driver's outgoing queue. They just set the <structfield>type</structfield> and <structfield>memory</structfield> <structfield>type</structfield>, <structfield>memory</structfield> and <structfield>reserved</structfield> fields of a &v4l2-buffer; as above, when <constant>VIDIOC_DQBUF</constant> is called with a pointer to this structure the driver fills the remaining fields or returns an error code.</para> Loading
