In 2008 when this documentation was added, it was probably possible to use the accelerometer play neverball "out of the box" as described. That's not the case any more though. After fixing sdl to expose the device again (https://bugzilla.libsdl.org/show_bug.cgi?id=4789), the game is unplayable because modern versions of neverball configure the 3rd axis (usually the twisting action of a physical joystick) to rotate the field of view by default. Since the Z axis is ordinarily fully positive (as documented), this results in the field of view constantly rotating and the game is unplayable. Until I went closer into the details, this had me thinking that the accelerometer was not working correctly. Update the documentation to clarify. Signed-off-by: Daniel Drake <drake@xxxxxxxxxxxx> --- Documentation/misc-devices/lis3lv02d.rst | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/Documentation/misc-devices/lis3lv02d.rst b/Documentation/misc-devices/lis3lv02d.rst index 959bd2b822cf..c6d3f2d616a4 100644 --- a/Documentation/misc-devices/lis3lv02d.rst +++ b/Documentation/misc-devices/lis3lv02d.rst @@ -20,7 +20,7 @@ This driver provides support for the accelerometer found in various HP laptops sporting the feature officially called "HP Mobile Data Protection System 3D" or "HP 3D DriveGuard". It detects automatically laptops with this sensor. Known models (full list can be found in drivers/platform/x86/hp_accel.c) will have -their axis automatically oriented on standard way (eg: you can directly play +their axis automatically oriented on standard way (eg: you can play neverball). The accelerometer data is readable via /sys/devices/platform/lis3lv02d. Reported values are scaled to mg values (1/1000th of earth gravity). @@ -72,8 +72,7 @@ Axes orientation ---------------- For better compatibility between the various laptops. The values reported by -the accelerometer are converted into a "standard" organisation of the axes -(aka "can play neverball out of the box"): +the accelerometer are converted into a "standard" organisation of the axes: * When the laptop is horizontal the position reported is about 0 for X and Y and a positive value for Z @@ -82,6 +81,10 @@ the accelerometer are converted into a "standard" organisation of the axes (becomes negative) * If the laptop is put upside-down, Z becomes negative +This configuration of X and Y axes works for playing neverball, as long +as you configure it to ignore the Z axis (e.g. in neverballrc, set +joystick_axis_x1 to point to a non-existent axis). + If your laptop model is not recognized (cf "dmesg"), you can send an email to the maintainer to add it to the database. When reporting a new laptop, please include the output of "dmidecode" plus the value of -- 2.20.1
