Thread (11 messages) 11 messages, 4 authors, 2016-05-30

[PATCH 0/2] ARM: dts: Fix imprecise external abort error when accessing Exynos MFC

From: Javier Martinez Canillas <hidden>
Date: 2016-05-25 14:18:25
Also in: linux-clk, linux-devicetree, linux-samsung-soc, lkml

Hello Marek,

On 05/25/2016 02:51 AM, Marek Szyprowski wrote:
Hello,


On 2016-05-24 19:41, Javier Martinez Canillas wrote:
quoted
This series fixes an imprecise external abort error when accessing the
Exynos MFC registers due the power domain configuration requiring the
aclk333 clock to be enabled during a domain switch.

There isn't a dependency between the clock and Linux Samsung SoC trees
because the CLK_ACLK333 clock ID is already defined so the patches can
be picked indepedently by the relevant subsystem maintainers.
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

I'm really curious what kind of async-bridge is there, but this patch
really fixes the problem with mfc power domain.
Yes, the Exynos manual is not that clear about what clocks have to remain
enabled during a power domain switch for an IP block so maybe I got wrong.

I see that the MFC block has an async-bridge in "Figure 15-1" at section 
"15.2.1 NoC Probes in 5420 Bus". And I thought that since the IP block
has an async-bridge, the clock needs to remain ungated when the PMU turn
it on and off on a power domain switch.

I chose that clock because "Figure 7-10 MFC Clock Diagram" at section
"7.4.7 MFC Clock Diagram" shows that ACLK_333 is associated with the
MFC internal buses, or at least that's my understanding.

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America
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