[PATCH v2 2/2] Doc/ABI: sysfs-drm initial document; "polled" entry
Andy Walls
awalls at md.metrocast.net
Tue Sep 21 20:20:22 PDT 2010
This is the initial addition of documentation for the drm module's sysfs
entries. It provides a drm sysfs entries overview, and a detailed
description of the new drm per output connector "polled" entry in sysfs.
Signed-of-by: Andy Walls <awalls at md.metrocast.net>
diff --git a/Documentation/ABI/testing/sysfs-drm b/Documentation/ABI/testing/sysfs-drm
new file mode 100644
index 0000000..18a017a
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-drm
@@ -0,0 +1,208 @@
+Direct Rendering Infrastructure (DRI) Direct Rendering Manager (drm) module
+and Translation Table Manager (ttm) module sysfs entries
+
+Example class view showing a single graphics adapter with three output
+connectors, a special control device node for the graphics adapter, and the
+Translation Table Manager (ttm) graphics memory manager virtual device:
+
+ /sys/class/drm/
+ ├── card0 -> ../../devices/<...>/drm/card0
+ ├── card0-DVI-D-1 -> ../../devices/<...>/drm/card0/card0-DVI-D-1
+ ├── card0-HDMI Type A-1 -> ../../devices/<...>/drm/card0/card0-HDMI Type A-1
+ ├── card0-VGA-1 -> ../../devices/<...>/drm/card0/card0-VGA-1
+ ├── controlD64 -> ../../devices/<...>/drm/controlD64
+ ├── ttm -> ../../devices/virtual/drm/ttm
+ └── version
+
+ 6 directories, 1 file
+
+
+Corresponding DRI device nodes for the example graphics adapter, with
+additional ACL properties on card0 granting rw perms to the X/console user:
+
+ crw-rw----+ 1 root video 226, 0 2010-09-21 20:52 /dev/dri/card0
+ crw-rw-rw-. 1 root video 226, 64 2010-09-21 20:51 /dev/dri/controlD64
+
+
+Example physical device view for a single graphics adapter with three output
+connectors and a special control device node for the graphics adapter:
+
+ /sys/devices/<...>/drm
+ ├── card0
+ │ ├── card0-DVI-D-1
+ │ │ ├── device -> ../../card0
+ │ │ ├── dpms
+ │ │ ├── edid
+ │ │ ├── enabled
+ │ │ ├── modes
+ │ │ ├── polled
+ │ │ ├── power
+ │ │ │ ├── control
+ │ │ │ ├── runtime_active_time
+ │ │ │ ├── runtime_status
+ │ │ │ ├── runtime_suspended_time
+ │ │ │ ├── wakeup
+ │ │ │ └── wakeup_count
+ │ │ ├── status
+ │ │ ├── subsystem -> ../../../../../../../class/drm
+ │ │ └── uevent
+ │ ├── card0-HDMI Type A-1
+ │ │ ├── device -> ../../card0
+ │ │ ├── dpms
+ │ │ ├── edid
+ │ │ ├── enabled
+ │ │ ├── modes
+ │ │ ├── polled
+ │ │ ├── power
+ │ │ │ ├── control
+ │ │ │ ├── runtime_active_time
+ │ │ │ ├── runtime_status
+ │ │ │ ├── runtime_suspended_time
+ │ │ │ ├── wakeup
+ │ │ │ └── wakeup_count
+ │ │ ├── status
+ │ │ ├── subsystem -> ../../../../../../../class/drm
+ │ │ └── uevent
+ │ ├── card0-VGA-1
+ │ │ ├── device -> ../../card0
+ │ │ ├── dpms
+ │ │ ├── edid
+ │ │ ├── enabled
+ │ │ ├── modes
+ │ │ ├── polled
+ │ │ ├── power
+ │ │ │ ├── control
+ │ │ │ ├── runtime_active_time
+ │ │ │ ├── runtime_status
+ │ │ │ ├── runtime_suspended_time
+ │ │ │ ├── wakeup
+ │ │ │ └── wakeup_count
+ │ │ ├── status
+ │ │ ├── subsystem -> ../../../../../../../class/drm
+ │ │ └── uevent
+ │ ├── dev
+ │ ├── device -> ../../../0000:01:05.0
+ │ ├── power
+ │ │ ├── control
+ │ │ ├── runtime_active_time
+ │ │ ├── runtime_status
+ │ │ ├── runtime_suspended_time
+ │ │ ├── wakeup
+ │ │ └── wakeup_count
+ │ ├── subsystem -> ../../../../../../class/drm
+ │ └── uevent
+ └── controlD64
+ ├── dev
+ ├── device -> ../../../0000:01:05.0
+ ├── power
+ │ ├── control
+ │ ├── runtime_active_time
+ │ ├── runtime_status
+ │ ├── runtime_suspended_time
+ │ ├── wakeup
+ │ └── wakeup_count
+ ├── subsystem -> ../../../../../../class/drm
+ └── uevent
+
+ 20 directories, 55 files
+
+
+Example virtual device view view showing the Translation Table Manager (ttm)
+graphics memory manager virtual device:
+
+ /sys/devices/virtual/drm
+ └── ttm
+ ├── buffer_objects
+ │ └── bo_count
+ ├── memory_accounting
+ │ ├── kernel
+ │ │ ├── available_memory
+ │ │ ├── emergency_memory
+ │ │ ├── swap_limit
+ │ │ ├── used_memory
+ │ │ └── zone_memory
+ │ └── pool
+ │ ├── pool_allocation_size
+ │ ├── pool_max_size
+ │ └── pool_small_allocation
+ ├── power
+ │ ├── control
+ │ ├── runtime_active_time
+ │ ├── runtime_status
+ │ ├── runtime_suspended_time
+ │ ├── wakeup
+ │ └── wakeup_count
+ ├── subsystem -> ../../../../class/drm
+ └── uevent
+
+ 7 directories, 16 files
+
+
+
+Where: /sys/devices/<...>/drm/cardN/cardN-C-M/polled
+ For N a decimal system graphics adapter number: 0, 1, 2, ...
+ For C a connector type name (including spaces) from the set:
+ Unknown
+ VGA
+ DVI-I
+ DVI-D
+ DVI-A
+ Composite
+ SVIDEO
+ LVDS
+ Component
+ 9-pin DIN
+ DisplayPort
+ HDMI Type A
+ HDMI Type B
+ TV
+ Embedded DisplayPort
+ For M a decimal connector number for connectors of that type
+ over all the graphics adapters in the system: 1, 2, ...
+Date: 22 September 2010
+KernelVersion: 2.6.37
+Contact: Andy Walls <awalls at md.metrocast.net>
+Description:
+ Manual control over DRM Kernel Mode Set (KMS) output connector
+ hotplug/connect/disconnect polling criteria. The graphics
+ adapter drm driver (e.g. radeon, i915, nouveau) will detect
+ the available connectors on a graphics adapter and set polling
+ criteria flags for the connector to specify for what events the
+ 0.1 Hz DRM KMS poll of the connector should look.
+
+ A read of the contents of this entry will show what flags are
+ available, with the names of flags that are set for the
+ connector enclosed in brackets:
+
+ # cat /sys/devices/.../drm/card0/card0-DVI-D-1/polled
+ [hotplug_detectable] connect disconnect
+
+ A write of flags names to this entry, will clear the current
+ flag settings and set the poll criteria flags for that
+ connector to those specified names:
+
+ # echo " disconnect connect " > \
+ /sys/devices/.../drm/card0/card0-DVI-D-1/polled
+ # cat /sys/devices/.../drm/card0/card0-DVI-D-1/polled
+ hotplug_detectable [connect] [disconnect]
+
+ # echo > /sys/devices/.../drm/card0/card0-DVI-D-1/polled
+ # cat /sys/devices/.../drm/card0/card0-DVI-D-1/polled
+ hotplug_detectable connect disconnect
+
+ The flags have the following meanings in drm_crtc_helper.c:
+
+ hotplug_detectable:
+ always attempt to detect connection status upon poll
+ don't automatically set up another poll of connector
+
+ connect:
+ attempt to detect "connect" events
+ automatically set up another poll of connector
+
+ disconnect:
+ attempt to detect "disconnect" events
+ automatically set up another poll of connector
+
+ Clearing all three flags will disable any detection actions
+ being taken for that connector during the 0.1 Hz poll.
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