Hi, I've got a little problem with the ALPS touchpad in my Dell Inspiron 8200 (identified as E7 report: 32 02 14). Sometimes when pressing the touchpad buttons, they get stuck (in the driver only, of course :-) and are released only after moving the finger on the touchpad. This behaviour started after upgrading to kernel 2.6.32.8. With the 2.6.26.5 kernel I was using previously, it didn't occur. I identified the change causing this to be the following one from Ulrich Dangel: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d7ed5d883c09c5474f842dcb148515dfaef2a567 > Input: ALPS - handle touchpoints buttons correctly > > When pressing any button belonging to the touchpoint, the generated > click events don't belong to the touchpoint but to the touchpad. > This patch fixes this behaviour, the events will be sent via the > correct device, so scrolling with touchpoint is possible. On my machine, this seems to sometimes direct the touchpad button release event to the touchpoint, causing the old touchpad button state to remain until the next packet from the touchpad arrives. Looking at the packets received, it's obvious why this happens: Normal left button down/up sequence: [ 269.805058] ff 11 20 49 32 00 [ 269.983019] ff 11 20 48 32 00 Broken left button down/up sequence: [ 273.947184] ff 11 20 49 32 00 [ 274.106059] ff 11 20 49 32 00 [ 274.262486] ff 00 00 08 00 7f As you can see, when the button gets stuck, the touchpad sends the button down event twice and instead of the normal button up event, it sends one with z==127 which Ulrich's change interprets as belonging to the touchpoint. Interestingly, kernel 2.6.32.8 already has all the code to fix this, it's just not enabled for my touchpad. alps_report_buttons() checks the ALPS_PS2_INTERLEAVED flag and if set, directs button up events to the same device that got the button down event, regardless of the source derived from the packet. Does anybody see a reason why this shouldn't be done unconditionally regardless of the ALPS_PS2_INTERLEAVED flag? Or should there be another flag that enables the workaround just for selected models? Any other ideas how to fix this? Thanks, Martin -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
