Re: [RFC PATCH v3 2/2] clk: exynos5420: Make sure MDMA0 clock is enabled during suspend

[Kevin Hilman <khilman@kernel.org>]

Javier Martinez Canillas <javier.martinez@collabora.co.uk> writes:

[...]

> Yes, the following patch [0] is enough to make S2R working. If you think
> that is correct then I'll post it as a proper patch then.

[...]

> [0]
> From 78aa551ebcb9a4a7ae9d5581c33e0c0f19fe5ad6 Mon Sep 17 00:00:00 2001
> From: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
> Date: Tue, 7 Apr 2015 15:53:27 +0200
> Subject: [RFC PATCH] clk: exynos5420: Restore GATE_BUS_TOP on suspend
>
> Commit ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power
> Management support v12") added pm support for the pl330 dma driver but
> it makes the clock for the Exynos5420 MDMA0 DMA controller to be gated
> during suspend and this in turn makes its parent clock aclk266_g2d to
> be gated. But the clock needs to be ungated prior suspend to allow the
> system to be suspend and resumed correctly.
>
> Add GATE_BUS_TOP register to the list of registers to be restored when
> the system enters into a suspend state so aclk266_g2d will be ungated.
>
> Thanks to Abhilash Kesavan for figuring out that this was the issue.
>
> Fixes: ae43b32 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12")
> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>

Tested-by: Kevin Hilman <khilman@linaro.org>

on exynos5800-peach-pi

Kevin