From: javier.martinez@collabora•co.uk (Javier Martinez Canillas)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH v3 2/2] clk: exynos5420: Make sure MDMA0 clock is enabled during suspend
Date: Tue, 07 Apr 2015 13:56:37 +0200 [thread overview]
Message-ID: <5523C5F5.6000604@collabora.co.uk> (raw)
In-Reply-To: <5523B878.8040304@collabora.co.uk>
On 04/07/2015 12:59 PM, Javier Martinez Canillas wrote:
>
> So IIUC the CG_STATUS0 bits were a red herring and the real problem
> is that the aclk266_g2d needs to be enabled during suspend (although
> we still don't know why).
>
> It seems were are at a dead end now. Without being able to ask the HW
> Samsung folks we would never know what's going on here...
>
Ok, I found another interesting data point. ACLK_266_G2D has as
constraints that CG_STATUS0[21:22] needs to be 0 before gating
the clock and as I mentioned before those are associated with
the SSS and SSS_SLIM HW crypto modules according the docs I've.
So I looked at the clock used by the SSS module and found that
CLK_SSS parent is ACLK_266_G2D but CLK_SSS is never requested
since drivers/crypto/s5p-sss.c isn't built for exynos_defconfig.
Enabling CONFIG_CRYPTO_DEV_S5P makes the system to resume without
any patches since the sss clock prevents aclk266_g2d to be gated.
But I wanted to know if it was really aclk266_g2d that was needed
or the actual sss clock since the kernel didn't manage that clock
without the driver enabled.
So I disabled the sss clock before trying a S2R:
# devmem 0x10018800 32 0xFFFFFFFB
(CLK_SSS in CLK_GATE_IP_G2D is gated)
and S2R worked anyways but I see that CLK_GATE_IP_G2D is reset to
its default value on S2R so maybe that is why it works anyways?
# devmem 0x10018800
0xFFFFFFFF (all CLK_GATE_IP_G2D clocks enabled including CLK_SSS)
Does this shed any more light? Could the problem be that the sss
clock parent (aclk266_g2d) is gated during S2R? Is the SSS module
required for S2R or is just that CLK_SSS prevents the parent to
be gated and so it is another red herring?
Best regards,
Javier
next prev parent reply other threads:[~2015-04-07 11:56 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-30 15:53 [RFC PATCH v3 0/2] ARM: EXYNOS: Fix Suspend-to-RAM on Exynos5420 Javier Martinez Canillas
2015-03-30 15:53 ` [RFC PATCH v3 1/2] clk: samsung: Add a clock lookup function Javier Martinez Canillas
2015-03-30 16:02 ` Tomasz Figa
2015-03-30 16:08 ` Javier Martinez Canillas
2015-03-31 1:40 ` Michael Turquette
2015-03-31 8:59 ` Javier Martinez Canillas
2015-04-01 1:29 ` Michael Turquette
2015-04-01 8:26 ` Javier Martinez Canillas
2015-03-30 15:53 ` [RFC PATCH v3 2/2] clk: exynos5420: Make sure MDMA0 clock is enabled during suspend Javier Martinez Canillas
2015-03-30 16:07 ` Tomasz Figa
2015-03-30 16:16 ` Javier Martinez Canillas
[not found] ` <CAM4voanL3A=dS8Z-ovi_-EDi9ctyaxZkvjajp+3ZjyNAnqR1aQ@mail.gmail.com>
2015-03-31 20:00 ` Javier Martinez Canillas
2015-04-01 11:03 ` Sylwester Nawrocki
2015-04-01 11:44 ` Javier Martinez Canillas
2015-04-01 17:31 ` Sylwester Nawrocki
2015-04-01 22:31 ` Javier Martinez Canillas
2015-04-02 12:22 ` Abhilash Kesavan
2015-04-07 10:59 ` Javier Martinez Canillas
2015-04-07 11:56 ` Javier Martinez Canillas [this message]
2015-04-07 12:46 ` Tomasz Figa
2015-04-07 14:11 ` Javier Martinez Canillas
2015-04-07 14:38 ` Abhilash Kesavan
2015-04-07 15:00 ` Javier Martinez Canillas
2015-04-08 1:50 ` Abhilash Kesavan
2015-04-07 18:51 ` Kevin Hilman
2015-04-07 21:28 ` Tomasz Figa
2015-04-08 5:36 ` Javier Martinez Canillas
2015-04-07 14:11 ` Abhilash Kesavan
2015-04-07 14:26 ` Javier Martinez Canillas
2015-03-31 21:02 ` Kevin Hilman
2015-04-01 3:19 ` Abhilash Kesavan
2015-04-01 4:03 ` Kevin Hilman
2015-04-01 9:16 ` Krzysztof Kozlowski
2015-04-01 19:02 ` Michael Turquette
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