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 v4 0/6] drm: lcdif: Add i.MX93 LCDIF support
Date:   Fri, 17 Feb 2023 09:18:00 +0100
Message-ID: <13207614.uLZWGnKmhe@steina-w>
Organization: TQ-Systems GmbH
In-Reply-To: <20230217065407.2259731-1-victor.liu@nxp.com>
References: <20230217065407.2259731-1-victor.liu@nxp.com>
MIME-Version: 1.0
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Precedence: bulk

Hi Liu,

Am Freitag, 17. Februar 2023, 07:54:01 CET schrieb Liu Ying:
> Hi,
>=20
> This patch set aims to add i.MX93 LCDIF display controller support
> in the existing LCDIF DRM driver.  The LCDIF embedded in i.MX93 SoC
> is essentially the same to those embedded in i.MX8mp SoC.  Through
> internal bridges, i.MX93 LCDIF may drive a MIPI DSI display or a LVDS
> display or a parallel display.
>=20
> Patch 1/6 adds device tree binding support for i.MX93 LCDIF in the
> existing fsl,lcdif.yaml.
>=20
> Patch 2/6 drops lcdif->bridge NULL pointer check as a cleanup patch.
>=20
> Patch 3/6~5/6 prepare for adding i.MX93 LCDIF support step by step.
>=20
> Patch 6/6 adds i.MX93 LCDIF compatible string as the last step of
> adding i.MX93 LCDIF support.

Thanks for the series. I could test this on my TQMa93xxLA/MBa93xxCA with a=
=20
single LVDS display attached, so no DSI or parallel display. Hence I could =
not=20
test the bus format and flags checks, but they look okay.
So you can add
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
to the whole series as well.

One thing I noticed is that, sometimes it seems that before probing lcdif m=
y=20
system completely freezes. Adding some debug output it seems that's during=
=20
powering up the IMX93_MEDIABLK_PD_LCDIF power domain there is some race=20
condition. But adding more more detailed output made the problem go away.
Did you notice something similar? It might be a red hering though.

Best regards,
Alexander

>=20
> v3->v4:
> * Improve warning message when ignoring invalid LCDIF OF endpoint ids in
>   patch 5/6. (Alexander)
> * Use 'new_{c,p}state' instead of 'new_{crtc,plane}_state' in patch 3/6.
>   (Alexander)
> * Simplify lcdif_crtc_reset() by calling lcdif_crtc_atomic_destroy_state()
>   in patch 3/6. (Alexander)
> * Add '!crtc->state' check in lcdif_crtc_atomic_duplicate_state() in patch
> 3/6. (Alexander)
> * Collect Alexander's R-b tags on patch 1/6, 2/6 and 6/6.
>=20
> v2->v3:
> * Fix a trivial typo in patch 6/6's commit message.
>=20
> v1->v2:
> * Add Krzysztof's A-b and Marek's R-b tags on patch 1/6.
> * Split patch 2/2 in v1 into patch 2/6~6/6 in v2. (Marek, Alexander)
> * Drop '!remote ||' from lcdif_attach_bridge(). (Lothar)
> * Add comment on the 'base' member of lcdif_crtc_state structure to
>   note it should always be the first member. (Lothar)
> * Drop unneeded 'bridges' member from lcdif_drm_private structure.
> * Drop a comment about bridge input bus format from
> lcdif_crtc_atomic_check().
>=20
> Liu Ying (6):
>   dt-bindings: lcdif: Add i.MX93 LCDIF support
>   drm: lcdif: Drop unnecessary NULL pointer check on lcdif->bridge
>   drm: lcdif: Determine bus format and flags in ->atomic_check()
>   drm: lcdif: Check consistent bus format and flags across first bridges
>   drm: lcdif: Add multiple encoders and first bridges support
>   drm: lcdif: Add i.MX93 LCDIF compatible string
>=20
>  .../bindings/display/fsl,lcdif.yaml           |   7 +-
>  drivers/gpu/drm/mxsfb/lcdif_drv.c             |  71 ++++++-
>  drivers/gpu/drm/mxsfb/lcdif_drv.h             |   5 +-
>  drivers/gpu/drm/mxsfb/lcdif_kms.c             | 198 ++++++++++++------
>  4 files changed, 206 insertions(+), 75 deletions(-)


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