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Message-id: <5A55DD71.2060808@samsung.com>
Date: Wed, 10 Jan 2018 18:31:29 +0900
From: Chanwoo Choi <cw00.choi@samsung.com>
Organization: Samsung Electronics
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To: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
        Sylwester Nawrocki <s.nawrocki@samsung.com>, kgene@kernel.org,
        Tomasz Figa <tomasz.figa@gmail.com>, chanwoo@kernel.org,
        Jaehoon Chung <jh80.chung@samsung.com>,
        Inki Dae <inki.dae@samsung.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@codeaurora.org>, linux-clk@vger.kernel.org
Subject: Re: [PATCH 1/9] clk: samsung: exynos5433: Add clock flag to support
 suspend-to-ram
In-reply-to: <CAJKOXPc2Y0KX=gozGaMfJJM1B2gsPgLQ4rF5_R8wq5F6=Sxc7g@mail.gmail.com>
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References: <CGME20180109075905epcas1p1486543d8fec46f47d9d5ac350d841337@epcas1p1.samsung.com>
        <1515484746-10656-1-git-send-email-cw00.choi@samsung.com>
        <1515484746-10656-2-git-send-email-cw00.choi@samsung.com>
        <CAJKOXPc2Y0KX=gozGaMfJJM1B2gsPgLQ4rF5_R8wq5F6=Sxc7g@mail.gmail.com>
Sender: linux-kernel-owner@vger.kernel.org

On 2018년 01월 09일 20:44, Krzysztof Kozlowski wrote:
> On Tue, Jan 9, 2018 at 8:58 AM, Chanwoo Choi <cw00.choi@samsung.com> wrote:
>> This patch adds the CLK_IS_CRITICAL and CLK_IGNORE_UNUSED flag
>> to some clocks in order to avoid the hang-out in the suspend mode.
>>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> Cc: Tomasz Figa <tomasz.figa@gmail.com>
>> Cc: Michael Turquette <mturquette@baylibre.com>
>> Cc: Stephen Boyd <sboyd@codeaurora.org>
>> Cc: linux-clk@vger.kernel.org
>> ---
>>  drivers/clk/samsung/clk-exynos5433.c | 22 +++++++++++-----------
>>  1 file changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c
>> index db270908037a..3dc53cd0c730 100644
>> --- a/drivers/clk/samsung/clk-exynos5433.c
>> +++ b/drivers/clk/samsung/clk-exynos5433.c
>> @@ -583,25 +583,25 @@
>>                         CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, 0),
>>         GATE(CLK_ACLK_CAM1_333, "aclk_cam1_333", "div_aclk_cam1_333",
>>                         ENABLE_ACLK_TOP, 13,
>> -                       CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, 0),
>> +                       CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_CAM1_400, "aclk_cam1_400", "div_aclk_cam1_400",
>>                         ENABLE_ACLK_TOP, 12,
>>                         CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_CAM1_552, "aclk_cam1_552", "div_aclk_cam1_552",
>>                         ENABLE_ACLK_TOP, 11,
>> -                       CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, 0),
>> +                       CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_CAM0_333, "aclk_cam0_333", "div_aclk_cam0_333",
>>                         ENABLE_ACLK_TOP, 10,
>> -                       CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, 0),
>> +                       CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_CAM0_400, "aclk_cam0_400", "div_aclk_cam0_400",
>>                         ENABLE_ACLK_TOP, 9,
>>                         CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_CAM0_552, "aclk_cam0_552", "div_aclk_cam0_552",
>>                         ENABLE_ACLK_TOP, 8,
>> -                       CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, 0),
>> +                       CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_ISP_DIS_400, "aclk_isp_dis_400", "div_aclk_isp_dis_400",
>>                         ENABLE_ACLK_TOP, 7,
>> -                       CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED, 0),
>> +                       CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_ACLK_ISP_400, "aclk_isp_400", "div_aclk_isp_400",
>>                         ENABLE_ACLK_TOP, 6,
>>                         CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>> @@ -624,11 +624,11 @@
>>
>>         /* ENABLE_SCLK_TOP_CAM1 */
>>         GATE(CLK_SCLK_ISP_SENSOR2, "sclk_isp_sensor2", "div_sclk_isp_sensor2_b",
>> -                       ENABLE_SCLK_TOP_CAM1, 7, 0, 0),
>> +                       ENABLE_SCLK_TOP_CAM1, 7, CLK_IGNORE_UNUSED, 0),
>>         GATE(CLK_SCLK_ISP_SENSOR1, "sclk_isp_sensor1", "div_sclk_isp_sensor1_b",
>>                         ENABLE_SCLK_TOP_CAM1, 6, 0, 0),
>>         GATE(CLK_SCLK_ISP_SENSOR0, "sclk_isp_sensor0", "div_sclk_isp_sensor0_b",
>> -                       ENABLE_SCLK_TOP_CAM1, 5, 0, 0),
>> +                       ENABLE_SCLK_TOP_CAM1, 5, CLK_IGNORE_UNUSED, 0),
> 
> Marking this and few others related to ISP as ignore_unused or
> is_critical looks like a hacky workaround for wrong topology or
> missing clock users. The real cause should be fixed instead marking
> all the clocks as critical or ignore_unused.

I'm sorry. It is my mistake. When I tested the suspend again,
following three clocks need CLK_IS_CRITICAL flag.

- CLK_ACLK_CAM0_552 / CLK_SCLK_UFSUNIPRO_FSYS
  : there are not clk consumer until now.

- CLK_SCLK_AUD_UART is for serial_3.
  : There are no problem for the clocks of other serial port.
  Only this clock must need to enable it always on. If we have to
  handle CLK_SCLK_AUD_UART on drivers/tty/serial/samsung.c,
  we need to pass the 'serial port information and Exynos info'.
  So, If possible, adding the CLK_IS_CRITICAL flag to CLK_SCLK_AUD_UART
  is simple.

> 
> Best regards,
> Krzysztof
> 
>>         GATE(CLK_SCLK_ISP_MCTADC_CAM1, "sclk_isp_mctadc_cam1", "oscclk",
>>                         ENABLE_SCLK_TOP_CAM1, 4, 0, 0),
>>         GATE(CLK_SCLK_ISP_UART_CAM1, "sclk_isp_uart_cam1", "div_sclk_isp_uart",
>> @@ -636,7 +636,7 @@
>>         GATE(CLK_SCLK_ISP_SPI1_CAM1, "sclk_isp_spi1_cam1", "div_sclk_isp_spi1_b",
>>                         ENABLE_SCLK_TOP_CAM1, 1, 0, 0),
>>         GATE(CLK_SCLK_ISP_SPI0_CAM1, "sclk_isp_spi0_cam1", "div_sclk_isp_spi0_b",
>> -                       ENABLE_SCLK_TOP_CAM1, 0, 0, 0),
>> +                       ENABLE_SCLK_TOP_CAM1, 0, CLK_IGNORE_UNUSED, 0),
>>
>>         /* ENABLE_SCLK_TOP_DISP */
>>         GATE(CLK_SCLK_HDMI_SPDIF_DISP, "sclk_hdmi_spdif_disp",
>> @@ -654,7 +654,7 @@
>>                         ENABLE_SCLK_TOP_FSYS, 4, CLK_SET_RATE_PARENT, 0),
>>         GATE(CLK_SCLK_UFSUNIPRO_FSYS, "sclk_ufsunipro_fsys",
>>                         "div_sclk_ufsunipro", ENABLE_SCLK_TOP_FSYS,
>> -                       3, CLK_SET_RATE_PARENT, 0),
>> +                       3, CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, 0),
>>         GATE(CLK_SCLK_USBHOST30_FSYS, "sclk_usbhost30_fsys",
>>                         "div_sclk_usbhost30", ENABLE_SCLK_TOP_FSYS,
>>                         1, CLK_SET_RATE_PARENT, 0),
>> @@ -2982,7 +2982,7 @@ static void __init exynos5433_cmu_peris_init(struct device_node *np)
>>         GATE(CLK_PCLK_AUD_SLIMBUS, "pclk_aud_slimbus", "div_aclk_aud",
>>                         ENABLE_PCLK_AUD, 6, 0, 0),
>>         GATE(CLK_PCLK_AUD_UART, "pclk_aud_uart", "div_aclk_aud",
>> -                       ENABLE_PCLK_AUD, 5, 0, 0),
>> +                       ENABLE_PCLK_AUD, 5, CLK_IS_CRITICAL, 0),
>>         GATE(CLK_PCLK_AUD_PCM, "pclk_aud_pcm", "div_aclk_aud",
>>                         ENABLE_PCLK_AUD, 4, 0, 0),
>>         GATE(CLK_PCLK_AUD_I2S, "pclk_aud_i2s", "div_aclk_aud",
>> @@ -3008,7 +3008,7 @@ static void __init exynos5433_cmu_peris_init(struct device_node *np)
>>         GATE(CLK_SCLK_AUD_SLIMBUS, "sclk_aud_slimbus", "div_sclk_aud_slimbus",
>>                         ENABLE_SCLK_AUD1, 4, 0, 0),
>>         GATE(CLK_SCLK_AUD_UART, "sclk_aud_uart", "div_sclk_aud_uart",
>> -                       ENABLE_SCLK_AUD1, 3, CLK_IGNORE_UNUSED, 0),
>> +                       ENABLE_SCLK_AUD1, 3, CLK_IS_CRITICAL, 0),
>>         GATE(CLK_SCLK_AUD_PCM, "sclk_aud_pcm", "div_sclk_aud_pcm",
>>                         ENABLE_SCLK_AUD1, 2, 0, 0),
>>         GATE(CLK_SCLK_I2S_BCLK, "sclk_i2s_bclk", "ioclk_i2s_bclk",
>> --
>> 1.9.1
>>
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> 
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics