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Date:	Mon, 04 Jul 2016 11:40:15 +0200
From:	Sylwester Nawrocki <s.nawrocki@...sung.com>
To:	Andi Shyti <andi.shyti@...sung.com>
Cc:	Chanwoo Choi <cw00.choi@...sung.com>,
	Jaehoon Chung <jh80.chung@...sung.com>,
	Tomasz Figa <tomasz.figa@...il.com>,
	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	Kukjin Kim <kgene@...nel.org>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	linux-samsung-soc@...r.kernel.org, linux-clk@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Andi Shyti <andi@...zian.org>
Subject: Re: [PATCH v3 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for
 SPI clocks

On 06/30/2016 09:15 AM, Andi Shyti wrote:
> The CLK_IGNORE_UNUSED flag has to be avoided whenever possible.

In general I would rather disagree.

> Use the CLK_IS_CRITICAL flag instead for critical SPI1 clocks,
> which enables the clock line during boot time.
> 
> Suggested-by: Tomasz Figa <tomasz.figa@...il.com>
> Signed-off-by: Andi Shyti <andi.shyti@...sung.com>
> ---
>  drivers/clk/samsung/clk-exynos5433.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c
> index c3a5318..1f7c4951 100644
> --- a/drivers/clk/samsung/clk-exynos5433.c
> +++ b/drivers/clk/samsung/clk-exynos5433.c
> @@ -1662,7 +1662,7 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = {

> @@ -1677,7 +1677,7 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = {
>  	GATE(CLK_SCLK_SPI2, "sclk_spi2", "sclk_spi2_peric", ENABLE_SCLK_PERIC,
>  			5, CLK_SET_RATE_PARENT, 0),
>  	GATE(CLK_SCLK_SPI1, "sclk_spi1", "sclk_spi1_peric", ENABLE_SCLK_PERIC,
> -			4, CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0),
> +			4, CLK_IS_CRITICAL | CLK_SET_RATE_PARENT, 0),

As Tomasz pointed out, this should be addressed in the driver/dts,
we shouldn't be patching board configurations into a per-SoC driver.
Other boards may want to keep this clock disabled.

What is an exact problem here, are you perhaps testing suspend to RAM?
I tested my sound support patches on top of v4.7-rc1 and everything
seemed to work well, I didn't notice any issues with the audio codec
which was the only slave on the SPI 1 bus.

Doesn't it help when you specify CLK_SCLK_SPI1 as the second clock
("spi_busclk0") of the spi_1 bus controller instead of
CLK_SCLK_SPI0_PERIC? CLK_SCLK_SPI0_PERIC seem to be parent of
CLK_SCLK_SPI1 so the enable state would be propagated.


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