FP register corruption in Exynos 4210 (Cortex-A9)

Russell King - ARM Linux
2014-12-22T23:29:53Z

On Mon, Dec 22, 2014 at 07:46:27PM -0300, Lanchon wrote:
> however under some circumstances the kernel did the wrong thing: it didn't
> reload the registers even though it was needed, probably because the
> hardware had been powered down and had lost state without the tracking code
> getting word of it. just disabling the optimization made the kernel solid.

Right, so mainline kernel's don't exhibit the behaviour...

> a couple of days later the root cause seems to have been identified and
> fixed. i describe the whole thing here:
> http://forum.xda-developers.com/galaxy-s2/development-derivatives/kernel-fpbug-stable-4-x-kernel-galaxy-t2978088

... because it's a local issue with cpuidle not calling the appropriate
CPU PM functions, and that means there's no patches that we need to deal
with for mainline kernels, right?

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