Re: Synaptics and keyboard losing interrupts w/ACPI ?

Randy.Dunlap
2004-04-04T02:45:20Z

On Sat, 03 Apr 2004 18:09:09 -0800 Karl Hegbloom <hegbloom-tbDHPZwbsQQ@public.gmane.org> wrote:

| I apologize if this this is an FAQ or has already been answered; the
| sf.net list archive interface is... too feeble to suck. I wish they
| would switch to "lurker" (http://lurker.sourceforge.net/).

Yes, it needs help. :(

| I've got a laptop that has a synaptics touchpad. Every so often, with
| every kernel I've tried up through 2.6.4, the pointer will suddenly leap
| across the screen, and sometimes it will even push a GUI button there.
| Also, on occasion, a key will "stick down",,,,,,,,,,,, like that, until
| I push another key. Every now and then the keyboard quits working
| entirely, and I must reboot to regain control. When these things
| happen, I see, in the logs:
|
| Mar 29 08:04:37 localhost kernel: atkbd.c: Unknown key pressed (translated set 2, code 0x0 on isa0060/serio0).
| Mar 29 08:04:37 localhost kernel: atkbd.c: Use 'setkeycodes 00 <keycode>' to make it known.
| Mar 29 08:04:37 localhost kernel: atkbd.c: Unknown key pressed (translated set 2, code 0x0 on isa0060/serio0).
| Mar 29 08:04:37 localhost kernel: atkbd.c: Use 'setkeycodes 00 <keycode>' to make it known.
| Mar 29 08:04:37 localhost kernel: psmouse.c: TouchPad at isa0060/serio2/input0 lost synchronization, throwing 5 bytes away.
| Mar 29 08:05:16 localhost kernel: Synaptics driver lost sync at byte 4
| Mar 29 08:05:16 localhost kernel: Synaptics driver lost sync at byte 1
| Mar 29 08:05:16 localhost last message repeated 3 times
| Mar 29 08:05:16 localhost kernel: Synaptics driver resynced.
|
| There is also a message about an unknown scancode that also mentions
| that it's an XFree86 bug... that it should not access hardware
| directly. I also see that when I run the "console-tools" 'setkbdrate'
| command, which uses /dev/port to set the key repeat rate. The source
| mentions that on some architectures there's an ioctl for doing that. I
| am fairly certain that this "XFree86 bug" is probably not related to the
| other one or to ACPI.
|
| I am not the only one who experiences this problem, and this model of
| laptop is not the only one that supports this feature... After
| searching for those log messages at Google, I located several email
| messages saying things like that APM introduces latency to turn it off,
| and to try booting with "acpi=off" for similar reasons.
|
| Sure enough, when I boot with "acpi=off", the problem disappears
| entirely. The touchpad works perfectly, and the keyboard is fine.
|
| What I've decided is probably happening is that somewhere in the ACPI
| system, code is running for too long with interrupts disabled, so
| keyboard and touch-pad interrupts are being missed. What I want to know
| is, has this been reported before, and if so, has it been fixed since
| stock 2.6.4 was released? Will a patch from your sf site fix the
| problem?
|
| I sure wish I knew how to actually debug this kind of problem so that I
| could provide more specific information or a patch.

Have you tried any hints from the "2.6 input drivers FAQ"?
See http://lwn.net/Articles/69107/ or google for the string above.

--
~Randy