linux-kernel - Re: [PATCH v2 3/3] drm/ingenic: ipu: Only enable clock when needed

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Message-Id: <6RIAEQ.2KRLCE1YRKKB1@crapouillou.net>
Date:   Thu, 30 Jul 2020 18:21:05 +0200
From:   Paul Cercueil <paul@...pouillou.net>
To:     Sam Ravnborg <sam@...nborg.org>
Cc:     David Airlie <airlied@...ux.ie>, Daniel Vetter <daniel@...ll.ch>,
        od@...c.me, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/3] drm/ingenic: ipu: Only enable clock when needed



Le jeu. 30 juil. 2020 à 17:29, Sam Ravnborg <sam@...nborg.org> a 
écrit :
> On Thu, Jul 30, 2020 at 04:48:30PM +0200, Paul Cercueil wrote:
>>  Instead of keeping the IPU clock enabled constantly, enable and 
>> disable
>>  it on demand, when the IPU plane is used. That way, we won't use any
>>  extra power when the IPU is not used.
>> 
>>  v2: Explain the reason of this patch
>> 
>>  Signed-off-by: Paul Cercueil <paul@...pouillou.net>
> Reviewed-by: Sam Ravnborg <sam@...nborg.org>
> 
> And thanks for the quick update!

Pushed to drm-misc-next. Thanks!

Cheers,
-Paul

> 
> 	Sam
> 
>>  ---
>>   drivers/gpu/drm/ingenic/ingenic-ipu.c | 23 ++++++++++++++++++++---
>>   1 file changed, 20 insertions(+), 3 deletions(-)
>> 
>>  diff --git a/drivers/gpu/drm/ingenic/ingenic-ipu.c 
>> b/drivers/gpu/drm/ingenic/ingenic-ipu.c
>>  index 7dd2a6ae4994..fc8c6e970ee3 100644
>>  --- a/drivers/gpu/drm/ingenic/ingenic-ipu.c
>>  +++ b/drivers/gpu/drm/ingenic/ingenic-ipu.c
>>  @@ -49,6 +49,7 @@ struct ingenic_ipu {
>>   	struct regmap *map;
>>   	struct clk *clk;
>>   	const struct soc_info *soc_info;
>>  +	bool clk_enabled;
>> 
>>   	unsigned int num_w, num_h, denom_w, denom_h;
>> 
>>  @@ -288,12 +289,23 @@ static void 
>> ingenic_ipu_plane_atomic_update(struct drm_plane *plane,
>>   	const struct drm_format_info *finfo;
>>   	u32 ctrl, stride = 0, coef_index = 0, format = 0;
>>   	bool needs_modeset, upscaling_w, upscaling_h;
>>  +	int err;
>> 
>>   	if (!state || !state->fb)
>>   		return;
>> 
>>   	finfo = drm_format_info(state->fb->format->format);
>> 
>>  +	if (!ipu->clk_enabled) {
>>  +		err = clk_enable(ipu->clk);
>>  +		if (err) {
>>  +			dev_err(ipu->dev, "Unable to enable clock: %d\n", err);
>>  +			return;
>>  +		}
>>  +
>>  +		ipu->clk_enabled = true;
>>  +	}
>>  +
>>   	/* Reset all the registers if needed */
>>   	needs_modeset = drm_atomic_crtc_needs_modeset(state->crtc->state);
>>   	if (needs_modeset) {
>>  @@ -578,6 +590,11 @@ static void 
>> ingenic_ipu_plane_atomic_disable(struct drm_plane *plane,
>>   	regmap_clear_bits(ipu->map, JZ_REG_IPU_CTRL, JZ_IPU_CTRL_CHIP_EN);
>> 
>>   	ingenic_drm_plane_disable(ipu->master, plane);
>>  +
>>  +	if (ipu->clk_enabled) {
>>  +		clk_disable(ipu->clk);
>>  +		ipu->clk_enabled = false;
>>  +	}
>>   }
>> 
>>   static const struct drm_plane_helper_funcs 
>> ingenic_ipu_plane_helper_funcs = {
>>  @@ -761,9 +778,9 @@ static int ingenic_ipu_bind(struct device *dev, 
>> struct device *master, void *d)
>>   	drm_object_attach_property(&plane->base, ipu->sharpness_prop,
>>   				   ipu->sharpness);
>> 
>>  -	err = clk_prepare_enable(ipu->clk);
>>  +	err = clk_prepare(ipu->clk);
>>   	if (err) {
>>  -		dev_err(dev, "Unable to enable clock\n");
>>  +		dev_err(dev, "Unable to prepare clock\n");
>>   		return err;
>>   	}
>> 
>>  @@ -775,7 +792,7 @@ static void ingenic_ipu_unbind(struct device 
>> *dev,
>>   {
>>   	struct ingenic_ipu *ipu = dev_get_drvdata(dev);
>> 
>>  -	clk_disable_unprepare(ipu->clk);
>>  +	clk_unprepare(ipu->clk);
>>   }
>> 
>>   static const struct component_ops ingenic_ipu_ops = {
>>  --
>>  2.27.0