Re: [PATCH v4 1/4] gpu: drm: meson: Use devm_regulator_*get_enable*()

[Neil Armstrong]

Hi,

On 21/10/2022 17:02, Laurent Pinchart wrote:
> Hi Matti,
>
> On Fri, Oct 21, 2022 at 04:18:01PM +0300, Matti Vaittinen wrote:
> > Simplify using the devm_regulator_get_enable_optional(). Also drop the
> > seemingly unused struct member 'hdmi_supply'.
> >
> > Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
> >
> > ---
> > v3 => v4:
> > - split meson part to own patch
> >
> > RFCv1 => v2:
> > - Change also sii902x to use devm_regulator_bulk_get_enable()
> >
> > Please note - this is only compile-tested due to the lack of HW. Careful
> > review and testing is _highly_ appreciated.
> > ---
> >   drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
> >   1 file changed, 3 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> > index 5cd2b2ebbbd3..7642f740272b 100644
> > --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> > +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> > @@ -140,7 +140,6 @@ struct meson_dw_hdmi {
> >   	struct reset_control *hdmitx_apb;
> >   	struct reset_control *hdmitx_ctrl;
> >   	struct reset_control *hdmitx_phy;
> > -	struct regulator *hdmi_supply;
> >   	u32 irq_stat;
> >   	struct dw_hdmi *hdmi;
> >   	struct drm_bridge *bridge;
> > @@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
> >   
> >   }
> >   
> > -static void meson_disable_regulator(void *data)
> > -{
> > -	regulator_disable(data);
> > -}
> > -
> >   static void meson_disable_clk(void *data)
> >   {
> >   	clk_disable_unprepare(data);
> > @@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
> >   	meson_dw_hdmi->data = match;
> >   	dw_plat_data = &meson_dw_hdmi->dw_plat_data;
> >   
> > -	meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev, "hdmi");
> > -	if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
> > -		if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
> > -			return -EPROBE_DEFER;
> > -		meson_dw_hdmi->hdmi_supply = NULL;
> > -	} else {
> > -		ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
> > -		if (ret)
> > -			return ret;
> > -		ret = devm_add_action_or_reset(dev, meson_disable_regulator,
> > -					       meson_dw_hdmi->hdmi_supply);
> > -		if (ret)
> > -			return ret;
> > -	}
> > +	ret = devm_regulator_get_enable_optional(dev, "hdmi");
> > +	if (ret != -ENODEV)
> > +		return ret;
>
> As noted in the review of the series that introduced
> devm_regulator_get_enable_optional(), the right thing to do is to
> implement runtime PM in this driver to avoid wasting power.

While I agree, it's not really the same level of effort as this patch
should be functionally equivalent.

> >   
> >   	meson_dw_hdmi->hdmitx_apb = devm_reset_control_get_exclusive(dev,
> >   						"hdmitx_apb");

Neil