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Bug 3193 - Dualshock 3's motion sensors overwrite analog stick
Summary: Dualshock 3's motion sensors overwrite analog stick
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: joystick (show other bugs)
Version: 1.2.15
Hardware: x86_64 Linux
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-12-03 16:40 UTC by maxxus
Modified: 2018-11-14 21:38 UTC (History)
2 users (show)

See Also:

Attachments
src/joystick/linux/SDL_sysjoystick.patch (2.07 KB, text/plain)
2015-12-03 16:40 UTC, maxxus 		Details
linux sys_joystick patch (1.22 KB, patch)
2018-07-31 10:51 UTC, Ozkan Sezer 		Details | Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description maxxus 2015-12-03 16:40:26 UTC 
Created attachment 2320 [details]
src/joystick/linux/SDL_sysjoystick.patch

The Dualshock 3's motion sensors don't seem to be reported by the call to EVIOCGBIT but they still send EV_ABS events.  Because they're not reported by EVIOCGBIT they're not assigned a proper axis ids and the default of 0 is used, which is the valid id for the left analog sticks left/right axis.

The attached patch sets the default axis id to ABS_MAX, and then checks the axis id before performing the update.  This will protect against EV_ABS events for axes that aren't reported or handled correctly.
Comment 1 Ozkan Sezer 2018-07-31 10:51:17 UTC 
Created attachment 3275 [details]
linux sys_joystick patch

The original patch does not apply because it is whitespace-mangled.
Attaching a one that applies to current SDL-1.2 branch.

Has anyone tried this anyway?
Comment 2 maxxus 2018-08-07 03:13:12 UTC 
I only know of one other person to use the patch and it seemed to fix their problem as well (https://forums.pcsx2.net/Thread-OnePAD-Dualshock-3-on-Linux?pid=490821#pid490821).

Considering that this bug report and patch is over 3 years old now, I don't know if the problem still persists for the Dualshock 3.  Maybe the motion sensors are correctly reported now, I don't have a setup to test with currently.

In general though the patch protects against any axis that isn't reported by EVIOCGBIT but still sends EV_ABS events; It's not specific to the Dualshock 3.
Comment 3 Ozkan Sezer 2018-08-07 07:10:50 UTC 
This patch is in:  https://hg.libsdl.org/SDL/rev/3e05d58dc84f

Thanks.  Closing as fixed.
Comment 4 Sam Lantinga 2018-11-14 21:38:17 UTC 
This is fixed for SDL 2.0 here:
https://hg.libsdl.org/SDL/rev/a7ee81795c75

Thanks!