Bug 17842

Summary: 2.6.34 breaks appletouch in older Powerbooks
Product: Drivers Reporter: Risto A. Paju (teknohog)
Component: Input DevicesAssignee: drivers_input-devices
Status: RESOLVED PATCH_ALREADY_AVAILABLE    
Severity: normal CC: dmitry.torokhov
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.34 to 2.6.35.4 Subsystem:
Regression: No Bisected commit-id:
Attachments: Revert appletouch.c back to 2.6.33

Description Risto A. Paju 2010-09-05 15:58:29 UTC 
Created attachment 29052 [details]
Revert appletouch.c back to 2.6.33

Commit 04b4b88cca0ebe3813b4b6f014fb6a0db380b137 fixed an integer overflow issue in the Apple touchpad driver, improving functionality in newer Powerbooks. Unfortunately, this introduces problems in older Powerbooks: only a part of the touchpad works properly, and some areas work in inverted directions.

My Powerbook A1106 is affected, another report of the same problem is at
http://old.nabble.com/2.6.34-rc--%2B-appletouch-%2B-Regression-td28307993.html

As a temporary solution, the old appletouch.c from the 2.6.33 series can be used as such in current kernels. The file can be replaced directly, or my patch can be used to the same effect.

However, a nicer long-term solution would be a parameter to change the behaviour. This way the same driver could be used in all Powerbooks.
Comment 1 Dmitry Torokhov 2010-09-05 20:36:47 UTC 
The offending change has been reverted form mainline, I guess we need to do the same for stable.