From:   Alexander Stein <alexander.stein@ew.tq-group.com>
To:     dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Liu Ying <victor.liu@nxp.com>
Cc:     marex@denx.de, stefan@agner.ch, airlied@gmail.com, daniel@ffwll.ch,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de,
        festevam@gmail.com, linux-imx@nxp.com,
        krzysztof.kozlowski@linaro.org, LW@karo-electronics.de
Subject: Re: [PATCH v3 2/6] drm: lcdif: Drop unnecessary NULL pointer check on lcdif->bridge
Date:   Tue, 14 Feb 2023 14:42:54 +0100
Message-ID: <10229432.nUPlyArG6x@steina-w>
Organization: TQ-Systems GmbH
In-Reply-To: <20230213085612.1026538-3-victor.liu@nxp.com>
References: <20230213085612.1026538-1-victor.liu@nxp.com> <20230213085612.1026538-3-victor.liu@nxp.com>
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Precedence: bulk

Hi Liu,

thanks for the update.

Am Montag, 13. Februar 2023, 09:56:08 CET schrieb Liu Ying:
> A valid bridge is already found in lcdif_attach_bridge() and set
> to lcdif->bridge, so lcdif->bridge cannot be a NULL pointer. Drop
> the unnecessary NULL pointer check in KMS stage.
>=20
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v2->v3:
> * No change.
>=20
> v1->v2:
> * Split from patch 2/2 in v1. (Marek, Alexander)
>=20
>  drivers/gpu/drm/mxsfb/lcdif_kms.c | 33 +++++++++++--------------------
>  1 file changed, 12 insertions(+), 21 deletions(-)
>=20
> diff --git a/drivers/gpu/drm/mxsfb/lcdif_kms.c
> b/drivers/gpu/drm/mxsfb/lcdif_kms.c index 262bc43b1079..e54200a9fcb9 1006=
44
> --- a/drivers/gpu/drm/mxsfb/lcdif_kms.c
> +++ b/drivers/gpu/drm/mxsfb/lcdif_kms.c
> @@ -394,7 +394,7 @@ static void lcdif_crtc_mode_set_nofb(struct
> lcdif_drm_private *lcdif, struct drm_display_mode *m =3D
> &lcdif->crtc.state->adjusted_mode;
>  	u32 bus_flags =3D 0;
>=20
> -	if (lcdif->bridge && lcdif->bridge->timings)
> +	if (lcdif->bridge->timings)
>  		bus_flags =3D lcdif->bridge->timings->input_bus_flags;
>  	else if (bridge_state)
>  		bus_flags =3D bridge_state->input_bus_cfg.flags;
> @@ -463,30 +463,21 @@ static void lcdif_crtc_atomic_enable(struct drm_crtc
> *crtc, struct drm_display_mode *m =3D &lcdif->crtc.state->adjusted_mode;
>  	struct drm_bridge_state *bridge_state =3D NULL;
>  	struct drm_device *drm =3D lcdif->drm;
> -	u32 bus_format =3D 0;
> +	u32 bus_format;
>  	dma_addr_t paddr;
>=20
> -	/* If there is a bridge attached to the LCDIF, use its bus format */
> -	if (lcdif->bridge) {
> -		bridge_state =3D
> -			drm_atomic_get_new_bridge_state(state,
> -							lcdif-
>bridge);
> -		if (!bridge_state)
> -			bus_format =3D MEDIA_BUS_FMT_FIXED;
> -		else
> -			bus_format =3D bridge_state->input_bus_cfg.format;
> -
> -		if (bus_format =3D=3D MEDIA_BUS_FMT_FIXED) {
> -			dev_warn_once(drm->dev,
> -				      "Bridge does not provide bus=20
format, assuming
> MEDIA_BUS_FMT_RGB888_1X24.\n" -				     =20
"Please fix bridge driver by
> handling atomic_get_input_bus_fmts.\n"); -		=09
bus_format =3D
> MEDIA_BUS_FMT_RGB888_1X24;
> -		}
> -	}
> +	bridge_state =3D drm_atomic_get_new_bridge_state(state, lcdif-
>bridge);
> +	if (!bridge_state)
> +		bus_format =3D MEDIA_BUS_FMT_FIXED;
> +	else
> +		bus_format =3D bridge_state->input_bus_cfg.format;
>=20
> -	/* If all else fails, default to RGB888_1X24 */
> -	if (!bus_format)
> +	if (bus_format =3D=3D MEDIA_BUS_FMT_FIXED) {
> +		dev_warn_once(drm->dev,
> +			      "Bridge does not provide bus format,=20
assuming
> MEDIA_BUS_FMT_RGB888_1X24.\n" +			      "Please fix=20
bridge driver by
> handling atomic_get_input_bus_fmts.\n"); bus_format =3D
> MEDIA_BUS_FMT_RGB888_1X24;
> +	}
>=20
>  	clk_set_rate(lcdif->clk, m->crtc_clock * 1000);


LGTM.
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>

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