Re: Lenovo 3000 N100 i8042 problems

On Wed, 3 Sep 2008, Daniel Barkalow wrote:

On Wed, 3 Sep 2008, Dmitry Torokhov wrote:

On Tue, Sep 02, 2008 at 12:16:15PM -0400, Daniel Barkalow wrote:
legacy mode only has a bug that doesn't matter to Windows, and active mux
may have some of the usual problems but nothing I particularly noticed.

I noticed that, when my i8042 would stop working, it would generally have
just delivered one mouse interrupt to CPU1 after never previously doing
so. Perhaps there's some sort of deadlock in the Linux i8042 driver when
both cores are unexpectedly getting interrupts from the two devices at
once? I could understand there being a Linux bug only triggered by quirky
hardware that only applies to legacy mode, which was just uncovered by
this patch.


I am not sure, internally we the kernel still deals with 2 interrupt
sources (KBD and AUX) regardless whether it is in legacy or active
multiplexing mode...

Does it take long to trigger the bug? You coudl try doing "echo 1 >
/sys/modules/i8042/parameters/debug" and thend me dmesg or
/var/log/messages after the bug was triggered - I might see something
there. But please be aware that if you send me such a log I can decode
everything that you have been typing...

It's usually within an hour of the right usage pattern. I'll try to
trigger it with debugging on while not typing anything secret Thursday
evening.

Attached. This has me typing some unimportant stuff, and then it sticks,
then I plug in a USB keyboard, then I tried unbinding the i8042 and
binding it again; the audio stuttered briefly, and recovered, and I did it
again, and then saved this log.

-Daniel
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