Messages in this thread | | | Date | Tue, 24 Feb 2015 17:46:32 +0900 | From | Chanwoo Choi <> | Subject | Re: [RESEND PATCH] ARM: EXYNOS: Fix failed second suspend on Exynos4 |
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On 02/18/2015 07:45 PM, Krzysztof Kozlowski wrote: > On Exynos4412 boards (Trats2, Odroid U3) after enabling L2 cache in > 56b60b8bce4a ("ARM: 8265/1: dts: exynos4: Add nodes for L2 cache > controller") the second suspend to RAM failed. First suspend worked fine > but the next one hang just after powering down of secondary CPUs (system > consumed energy as it would be running but was not responsive). > > The issue was caused by enabling delayed reset assertion for CPU0 just > after issuing power down of cores. This was introduced for Exynos4 in > 13cfa6c4f7fa ("ARM: EXYNOS: Fix CPU idle clock down after CPU off"). > > The whole behavior is not well documented but after checking with vendor > code this should be done like this (on Exynos4): > 1. Enable delayed reset assertion when system is running (for all CPUs). > 2. Disable delayed reset assertion before suspending the system. > This can be done after powering off secondary CPUs. > 3. Re-enable the delayed reset assertion when system is resumed. > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > Fixes: 13cfa6c4f7fa ("ARM: EXYNOS: Fix CPU idle clock down after CPU off") > Cc: <stable@vger.kernel.org> > --- > arch/arm/mach-exynos/common.h | 2 ++ > arch/arm/mach-exynos/exynos.c | 27 +++++++++++++++++++++++++++ > arch/arm/mach-exynos/platsmp.c | 39 ++------------------------------------- > arch/arm/mach-exynos/suspend.c | 3 +++ > 4 files changed, 34 insertions(+), 37 deletions(-)
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
I tested this patch on Exynos4412-baed TRATS2 board.
Thanks, Chanwoo Choi
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