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: Mon, 30 Mar 2015 18:16:49 +0200 [thread overview]
Message-ID: <551976F1.1000605@collabora.co.uk> (raw)
In-Reply-To: <CA+Ln22FBpuzR06qCsVc7SXtLX2mhf901vDE5D-mT1+ijZ2G3sg@mail.gmail.com>
Hello Tomasz,
Thanks a lot for your feedback.
On 03/30/2015 06:07 PM, Tomasz Figa wrote:
> Hi Javier,
>
> Please see my comments inline.
>
> 2015-03-31 0:53 GMT+09:00 Javier Martinez Canillas
> <javier.martinez@collabora•co.uk>:
> [snip]
>> diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
>> index 07d666cc6a29..2d39b629144a 100644
>> --- a/drivers/clk/samsung/clk-exynos5420.c
>> +++ b/drivers/clk/samsung/clk-exynos5420.c
>> @@ -151,6 +151,7 @@ enum exynos5x_plls {
>>
>> static void __iomem *reg_base;
>> static enum exynos5x_soc exynos5x_soc;
>> +struct samsung_clk_provider *ctx;
>
> static
>
Ok.
>>
>> #ifdef CONFIG_PM_SLEEP
>> static struct samsung_clk_reg_dump *exynos5x_save;
>> @@ -275,8 +276,18 @@ static const struct samsung_clk_reg_dump exynos5420_set_clksrc[] = {
>> { .offset = GATE_IP_PERIC, .value = 0xffffffff, },
>> };
>>
>> +/*
>> + * list of clocks that have to be kept enabled during suspend/resume cycle.
>> + */
>> +static unsigned int exynos5x_clk_suspend[] = {
>
> static const
>
Ok.
>> + CLK_MDMA0,
>> +};
>> +
>> static int exynos5420_clk_suspend(void)
>> {
>> + int i;
>> + struct clk *clk;
>> +
>> samsung_clk_save(reg_base, exynos5x_save,
>> ARRAY_SIZE(exynos5x_clk_regs));
>>
>> @@ -287,11 +298,24 @@ static int exynos5420_clk_suspend(void)
>> samsung_clk_restore(reg_base, exynos5420_set_clksrc,
>> ARRAY_SIZE(exynos5420_set_clksrc));
>>
>> + for (i = 0; i < ARRAY_SIZE(exynos5x_clk_suspend); i++) {
>> + clk = samsung_clk_lookup(ctx, exynos5x_clk_suspend[i]);
>
> If look-up speed is important here, maybe all the relevant clocks
> could be looked up once at initialization time and just prepared and
> enabled here?
>
Yes, I'll do that indeed.
In fact, I was wondering if we should let this clock be disabled at
all. I noticed that the rockchip clk drivers do something similar
and prepare / enable a list of clocks at init time [0,1].
Unfortunately I don't fully understand why this clock needs to be
enabled. It would be good if someone at Samsung can explain in
more detail what the real problem really is.
> Best regards,
> Tomasz
>
Best regards,
Javier
[0]: http://lxr.free-electrons.com/source/drivers/clk/rockchip/clk.c#L320
[1]: http://lxr.free-electrons.com/source/drivers/clk/rockchip/clk-rk3288.c#L874
next prev parent reply other threads:[~2015-03-30 16:16 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 [this message]
[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
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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