Re: [PATCH] input: Fix interrupt enable in i8042_ctr when enablinginterrupt fails

From: Steven Rostedt
Date: Mon Sep 10 2007 - 09:00:06 EST



--
On Mon, 10 Sep 2007, Markus Armbruster wrote:
>
> I believe this possible, but unlikely (perhaps not so unlikely on
> virtual machines). Scenarios involve enable succeeding the first
> time, failing the second time, and succeeding the third time. I can
> provide details, but the point I'd like to make is not that this is
> broken (although it is, strictly speaking), but that it is not
> obviously correct where it easily could be: just clear the interrupt
> enable bits when writing them to the hardware failed, like the old
> code did.
>

I also want to stress that this is more of a clean up for "technically
correct" code than a bug fix. This bug probably would never happen on
baremetal unless it was running on broken hardware.

BUT!!!

With more and more systems going to a virtual environment, having a bug or
some other anomaly can trigger the error that this patch prevents. The
patch will also trigger a print in the case of running on a buggy virtual
machine, which would help out the developers of that virtual machine to
fix their code.

Please apply.

-- Steve

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