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Message-ID: <b28836cc-d9cb-48c1-b4ee-402a4c752a28@vivo.com>
Date: Wed, 21 Aug 2024 11:23:45 +0800
From: Rong Qianfeng <11065417@...o.com>
To: wens@...e.org, Rong Qianfeng <rongqianfeng@...o.com>
Cc: Stefan Agner <stefan@...er.ch>, Alison Wang <alison.wang@....com>,
Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>,
Jernej Skrabec <jernej.skrabec@...il.com>,
Samuel Holland <samuel@...lland.org>, dri-devel@...ts.freedesktop.org,
linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-sunxi@...ts.linux.dev, opensource.kernel@...o.com
Subject: Re: [PATCH] gpu: drm: Use devm_clk_get_enabled() helpers
在 2024/8/20 21:51, Chen-Yu Tsai 写道:
> On Tue, Aug 20, 2024 at 8:59 PM Rong Qianfeng <rongqianfeng@...o.com> wrote:
>> Replace devm_clk_get() and clk_prepare_enable() with
>> devm_clk_get_enabled() that also disables and unprepares it on
>> driver detach.
>>
>> Signed-off-by: Rong Qianfeng <rongqianfeng@...o.com>
>> ---
>> drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 13 +++----------
>> drivers/gpu/drm/sun4i/sun6i_drc.c | 15 ++++-----------
>> drivers/gpu/drm/sun4i/sun8i_mixer.c | 13 +++----------
>> 3 files changed, 10 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> index ab6c0c6cd0e2..057dceaf079e 100644
>> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> @@ -284,16 +284,11 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
>> return PTR_ERR(fsl_dev->regmap);
>> }
>>
>> - fsl_dev->clk = devm_clk_get(dev, "dcu");
>> + fsl_dev->clk = devm_clk_get_enabled(dev, "dcu");
>> if (IS_ERR(fsl_dev->clk)) {
>> dev_err(dev, "failed to get dcu clock\n");
>> return PTR_ERR(fsl_dev->clk);
>> }
>> - ret = clk_prepare_enable(fsl_dev->clk);
>> - if (ret < 0) {
>> - dev_err(dev, "failed to enable dcu clk\n");
>> - return ret;
>> - }
>>
>> pix_clk_in = devm_clk_get(dev, "pix");
>> if (IS_ERR(pix_clk_in)) {
>> @@ -311,8 +306,7 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
>> div_ratio_shift, 8, CLK_DIVIDER_ROUND_CLOSEST, NULL);
>> if (IS_ERR(fsl_dev->pix_clk)) {
>> dev_err(dev, "failed to register pix clk\n");
>> - ret = PTR_ERR(fsl_dev->pix_clk);
>> - goto disable_clk;
>> + return PTR_ERR(fsl_dev->pix_clk);
>> }
>>
>> fsl_dev->tcon = fsl_tcon_init(dev);
>> @@ -341,8 +335,7 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
>> drm_dev_put(drm);
>> unregister_pix_clk:
>> clk_unregister(fsl_dev->pix_clk);
>> -disable_clk:
>> - clk_disable_unprepare(fsl_dev->clk);
>> +
>> return ret;
>> }
>>
>> diff --git a/drivers/gpu/drm/sun4i/sun6i_drc.c b/drivers/gpu/drm/sun4i/sun6i_drc.c
>> index 0d342f43fa93..f263ad282828 100644
>> --- a/drivers/gpu/drm/sun4i/sun6i_drc.c
>> +++ b/drivers/gpu/drm/sun4i/sun6i_drc.c
>> @@ -42,33 +42,28 @@ static int sun6i_drc_bind(struct device *dev, struct device *master,
>> return ret;
>> }
>>
>> - drc->bus_clk = devm_clk_get(dev, "ahb");
>> + drc->bus_clk = devm_clk_get_enabled(dev, "ahb");
> devm_* is actually not the correct thing to use in this case, as this
> is the component bind function, not the probe function. The lifetimes
> are not the same.
Thanks for your reminder, I didn't notice such a difference.
>
> We get away with devm_*_get because it's just a reference count,
> but devm_*_get_enabled is going to be worse, because the clock
> or whatever will not get disabled upon unbind. Same for sun8i_mixer.
>
> I just got bitten by this in an ASoC component driver, but the
> problem is similar.
Could you please post the log of the problem?
>
>
> ChenYu
>
>> if (IS_ERR(drc->bus_clk)) {
>> dev_err(dev, "Couldn't get our bus clock\n");
>> ret = PTR_ERR(drc->bus_clk);
>> goto err_assert_reset;
>> }
>> - clk_prepare_enable(drc->bus_clk);
>>
>> - drc->mod_clk = devm_clk_get(dev, "mod");
>> + drc->mod_clk = devm_clk_get_enabled(dev, "mod");
>> if (IS_ERR(drc->mod_clk)) {
>> dev_err(dev, "Couldn't get our mod clock\n");
>> ret = PTR_ERR(drc->mod_clk);
>> - goto err_disable_bus_clk;
>> + goto err_assert_reset;
>> }
>>
>> ret = clk_set_rate_exclusive(drc->mod_clk, 300000000);
>> if (ret) {
>> dev_err(dev, "Couldn't set the module clock frequency\n");
>> - goto err_disable_bus_clk;
>> + goto err_assert_reset;
>> }
>>
>> - clk_prepare_enable(drc->mod_clk);
>> -
>> return 0;
>>
>> -err_disable_bus_clk:
>> - clk_disable_unprepare(drc->bus_clk);
>> err_assert_reset:
>> reset_control_assert(drc->reset);
>> return ret;
>> @@ -80,8 +75,6 @@ static void sun6i_drc_unbind(struct device *dev, struct device *master,
>> struct sun6i_drc *drc = dev_get_drvdata(dev);
>>
>> clk_rate_exclusive_put(drc->mod_clk);
>> - clk_disable_unprepare(drc->mod_clk);
>> - clk_disable_unprepare(drc->bus_clk);
>> reset_control_assert(drc->reset);
>> }
>>
>> diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c
>> index bd0fe2c6624e..ebf00676a76d 100644
>> --- a/drivers/gpu/drm/sun4i/sun8i_mixer.c
>> +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
>> @@ -507,19 +507,18 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
>> return ret;
>> }
>>
>> - mixer->bus_clk = devm_clk_get(dev, "bus");
>> + mixer->bus_clk = devm_clk_get_enabled(dev, "bus");
>> if (IS_ERR(mixer->bus_clk)) {
>> dev_err(dev, "Couldn't get the mixer bus clock\n");
>> ret = PTR_ERR(mixer->bus_clk);
>> goto err_assert_reset;
>> }
>> - clk_prepare_enable(mixer->bus_clk);
>>
>> - mixer->mod_clk = devm_clk_get(dev, "mod");
>> + mixer->mod_clk = devm_clk_get_enabled(dev, "mod");
>> if (IS_ERR(mixer->mod_clk)) {
>> dev_err(dev, "Couldn't get the mixer module clock\n");
>> ret = PTR_ERR(mixer->mod_clk);
>> - goto err_disable_bus_clk;
>> + goto err_assert_reset;
>> }
>>
>> /*
>> @@ -530,8 +529,6 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
>> if (mixer->cfg->mod_rate)
>> clk_set_rate(mixer->mod_clk, mixer->cfg->mod_rate);
>>
>> - clk_prepare_enable(mixer->mod_clk);
>> -
>> list_add_tail(&mixer->engine.list, &drv->engine_list);
>>
>> base = sun8i_blender_base(mixer);
>> @@ -592,8 +589,6 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
>>
>> return 0;
>>
>> -err_disable_bus_clk:
>> - clk_disable_unprepare(mixer->bus_clk);
>> err_assert_reset:
>> reset_control_assert(mixer->reset);
>> return ret;
>> @@ -606,8 +601,6 @@ static void sun8i_mixer_unbind(struct device *dev, struct device *master,
>>
>> list_del(&mixer->engine.list);
>>
>> - clk_disable_unprepare(mixer->mod_clk);
>> - clk_disable_unprepare(mixer->bus_clk);
>> reset_control_assert(mixer->reset);
>> }
>>
>> --
>> 2.39.0
>>
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