[PATCH] ARM: EXYNOS: Fix coupled CPU idle freeze on Exynos4210

[Bartlomiej Zolnierkiewicz]

On Wednesday, March 21, 2018 10:45:05 AM Marek Szyprowski wrote:
> Since commit 04c8b0f82c7d ("irqchip/gic: Make locking a BL_SWITCHER only
> feature") coupled CPU idle freezes from time to time on Exynos4210. Later
> commit 313c8c16ee62 ("PM / CPU: replace raw_notifier with atomic_notifier")
> changed the context in which the CPU idle code is executed, what results
> in fully reproducible freeze all the time. However, almost the same coupled
> CPU idle code works fine on Exynos3250 regarless of the changes made in
> the mentioned commits.
> 
> It turned out that the IPI call used on Exynos4210 is conflicting with the
> change done in the first mentioned commit in GIC. Fix this by using the
> same code path as for Exynos3250, instead of the IPI call for
> synchronization with second CPU core, call dsb_sev() directly.
> 
> Tested on Exynos4210-based Trats and Origen boards.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> CC: stable at vger.kernel.org # v4.13+

Thanks for spotting and fixing this.

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics