Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 15 Apr 2021 11:26:33 +0200
From:   Maxime Ripard <maxime@cerno.tech>
To:     Paul Cercueil <paul@crapouillou.net>
Cc:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Simon Ser <contact@emersion.fr>,
        Sam Ravnborg <sam@ravnborg.org>, od@zcrc.me,
        linux-mips@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 2/2] drm/ingenic: Don't request full modeset if property
 is not modified
Message-ID: <20210415092633.4vkteqmqqxfgrjxz@gilmour>
References: <20210329175046.214629-1-paul@crapouillou.net>
 <20210329175046.214629-3-paul@crapouillou.net>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;
        protocol="application/pgp-signature"; boundary="rbolhufisrxhasd4"
Content-Disposition: inline
In-Reply-To: <20210329175046.214629-3-paul@crapouillou.net>
Precedence: bulk


--rbolhufisrxhasd4
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi,

On Mon, Mar 29, 2021 at 06:50:46PM +0100, Paul Cercueil wrote:
> Avoid requesting a full modeset if the sharpness property is not
> modified, because then we don't actually need it.
>=20
> Fixes: fc1acf317b01 ("drm/ingenic: Add support for the IPU")
> Cc: <stable@vger.kernel.org> # 5.8+
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
>  drivers/gpu/drm/ingenic/ingenic-ipu.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>=20
> diff --git a/drivers/gpu/drm/ingenic/ingenic-ipu.c b/drivers/gpu/drm/inge=
nic/ingenic-ipu.c
> index 3b1091e7c0cd..95b665c4a7b0 100644
> --- a/drivers/gpu/drm/ingenic/ingenic-ipu.c
> +++ b/drivers/gpu/drm/ingenic/ingenic-ipu.c
> @@ -640,10 +640,12 @@ ingenic_ipu_plane_atomic_set_property(struct drm_pl=
ane *plane,
>  {
>  	struct ingenic_ipu *ipu =3D plane_to_ingenic_ipu(plane);
>  	struct drm_crtc_state *crtc_state;
> +	bool mode_changed;
> =20
>  	if (property !=3D ipu->sharpness_prop)
>  		return -EINVAL;
> =20
> +	mode_changed =3D val !=3D ipu->sharpness;
>  	ipu->sharpness =3D val;
> =20
>  	if (state->crtc) {
> @@ -651,7 +653,7 @@ ingenic_ipu_plane_atomic_set_property(struct drm_plan=
e *plane,
>  		if (WARN_ON(!crtc_state))
>  			return -EINVAL;
> =20
> -		crtc_state->mode_changed =3D true;
> +		crtc_state->mode_changed |=3D mode_changed;
>  	}

I'd just change the condition from

if (state->crtc)

to

if (state->crtc && val !=3D ipu->sharpness)

It's going to be easier to extend if you ever need to. Also, drivers
usually do this in atomic_check, is there a specific reason to do it in
atomic_set_property?

Maxime

--rbolhufisrxhasd4
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCYHgGyAAKCRDj7w1vZxhR
xbrVAQD22j4BtDq6oO5iGWb7UdC+qPz36k0/YBh5BRbQ5qyf2gD+KYIoom5pUNBU
kg6Yl77CjwRcM0x0V2Ylhu7QwgWEpwA=
=U0dV
-----END PGP SIGNATURE-----

--rbolhufisrxhasd4--