diff options
| author | Breno Leitao <leitao@debian.org> | 2026-08-05 07:52:36 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-08-10 11:47:20 -1000 |
| commit | a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656 (patch) | |
| tree | 39f5b258386e1127d253d293194e9a2991bf3c34 /Documentation/input/devices/appletouch.rst | |
| download | linux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.tar.gz linux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.zip | |
workqueue: skip the node_nr_active update for non-unbound workqueuesgrafted
apply_wqattrs_commit() updates node_nr_active->max unconditionally.
wq->node_nr_active[] is only allocated for unbound workqueues, so guard
the call before per-cpu workqueues start using this path.
No functional change: only unbound workqueues reach apply_wqattrs_*()
today.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'Documentation/input/devices/appletouch.rst')
| -rw-r--r-- | Documentation/input/devices/appletouch.rst | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/Documentation/input/devices/appletouch.rst b/Documentation/input/devices/appletouch.rst new file mode 100644 index 000000000..c94470e66 --- /dev/null +++ b/Documentation/input/devices/appletouch.rst @@ -0,0 +1,94 @@ +.. include:: <isonum.txt> + +---------------------------------- +Apple Touchpad Driver (appletouch) +---------------------------------- + +:Copyright: |copy| 2005 Stelian Pop <stelian@popies.net> + +appletouch is a Linux kernel driver for the USB touchpad found on post +February 2005 and October 2005 Apple Aluminium Powerbooks. + +This driver is derived from Johannes Berg's appletrackpad driver [#f1]_, +but it has been improved in some areas: + + * appletouch is a full kernel driver, no userspace program is necessary + * appletouch can be interfaced with the synaptics X11 driver, in order + to have touchpad acceleration, scrolling, etc. + +Credits go to Johannes Berg for reverse-engineering the touchpad protocol, +Frank Arnold for further improvements, and Alex Harper for some additional +information about the inner workings of the touchpad sensors. Michael +Hanselmann added support for the October 2005 models. + +Usage +----- + +In order to use the touchpad in the basic mode, compile the driver and load +the module. A new input device will be detected and you will be able to read +the mouse data from /dev/input/mice (using gpm, or X11). + +In X11, you can configure the touchpad to use the synaptics X11 driver, which +will give additional functionalities, like acceleration, scrolling, 2 finger +tap for middle button mouse emulation, 3 finger tap for right button mouse +emulation, etc. In order to do this, make sure you're using a recent version of +the synaptics driver (tested with 0.14.2, available from [#f2]_), and configure +a new input device in your X11 configuration file (take a look below for an +example). For additional configuration, see the synaptics driver documentation:: + + Section "InputDevice" + Identifier "Synaptics Touchpad" + Driver "synaptics" + Option "SendCoreEvents" "true" + Option "Device" "/dev/input/mice" + Option "Protocol" "auto-dev" + Option "LeftEdge" "0" + Option "RightEdge" "850" + Option "TopEdge" "0" + Option "BottomEdge" "645" + Option "MinSpeed" "0.4" + Option "MaxSpeed" "1" + Option "AccelFactor" "0.02" + Option "FingerLow" "0" + Option "FingerHigh" "30" + Option "MaxTapMove" "20" + Option "MaxTapTime" "100" + Option "HorizScrollDelta" "0" + Option "VertScrollDelta" "30" + Option "SHMConfig" "on" + EndSection + + Section "ServerLayout" + ... + InputDevice "Mouse" + InputDevice "Synaptics Touchpad" + ... + EndSection + +Fuzz problems +------------- + +The touchpad sensors are very sensitive to heat, and will generate a lot of +noise when the temperature changes. This is especially true when you power-on +the laptop for the first time. + +The appletouch driver tries to handle this noise and auto adapt itself, but it +is not perfect. If finger movements are not recognized anymore, try reloading +the driver. + +You can activate debugging using the 'debug' module parameter. A value of 0 +deactivates any debugging, 1 activates tracing of invalid samples, 2 activates +full tracing (each sample is being traced):: + + modprobe appletouch debug=1 + +or:: + + echo "1" > /sys/module/appletouch/parameters/debug + + +.. Links: + +.. [#f1] http://johannes.sipsolutions.net/PowerBook/touchpad/ + +.. [#f2] `<http://web.archive.org/web/*/http://web.telia.com/~u89404340/touchpad/index.html>`_ |
