Revision 7f453c24b95a085fc7bd35d53b33abc4dc5a048b authored by Peter Zijlstra on 21 July 2009, 11:19:40 UTC, committed by Peter Zijlstra on 22 July 2009, 16:05:56 UTC
Anton noted that for inherited counters the counter-id as provided by PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID because each inherited counter gets its own id. His suggestion was to always return the parent counter id, since that is the primary counter id as exposed. However, these inherited counters have a unique identifier so that events like PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which counter gets modified, which is important when trying to normalize the sample streams. This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD, which is more useful anyway, since changing periods became a lot more common than initially thought -- rendering PERF_EVENT_PERIOD the less useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate value, since it reports the value used to trigger the overflow, whereas PERF_EVENT_PERIOD simply reports the requested period changed, which might only take effect on the next cycle). This still leaves us PERF_EVENT_THROTTLE to consider, but since that _should_ be a rare occurrence, and linking it to a primary id is the most useful bit to diagnose the problem, we introduce a PERF_SAMPLE_STREAM_ID, for those few cases where the full reconstruction is important. [Does change the ABI a little, but I see no other way out] Suggested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1248095846.15751.8781.camel@twins>
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appletouch.txt
Apple Touchpad Driver (appletouch)
----------------------------------
Copyright (C) 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[1], 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 [2]), 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:
------
[1]: http://johannes.sipsolutions.net/PowerBook/touchpad/
[2]: http://web.telia.com/~u89404340/touchpad/index.html
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