Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220922124306.34729-1-dev@pschenker.ch> <20220922124306.34729-4-dev@pschenker.ch>
In-Reply-To: <20220922124306.34729-4-dev@pschenker.ch>
From:   Adrien Grassein <adrien.grassein@gmail.com>
Date:   Thu, 22 Sep 2022 20:26:28 +0200
Message-ID: <CABkfQAG0ADPnJZAPBhq0ks-FCCNDw6qz4o+PBHniuqv+kiwSmg@mail.gmail.com>
Subject: Re: [PATCH 3/4] drm/bridge: lt8912b: fix corrupted image output
To:     Philippe Schenker <dev@pschenker.ch>
Cc:     dri-devel <dri-devel@lists.freedesktop.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Robert Foss <robert.foss@linaro.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Andrzej Hajda <andrzej.hajda@intel.com>,
        David Airlie <airlied@linux.ie>,
        Francesco Dolcini <francesco.dolcini@toradex.com>,
        Philippe Schenker <philippe.schenker@toradex.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Le jeu. 22 sept. 2022 =C3=A0 14:43, Philippe Schenker <dev@pschenker.ch> a =
=C3=A9crit :
>
> From: Francesco Dolcini <francesco.dolcini@toradex.com>
>
> Correct I2C address for the register list in lt8912_write_lvds_config(),
> these registers are on the first I2C address (0x48), the current
> function is just writing garbage to the wrong registers and this creates
> multiple issues (artifacts and output completely corrupted) on some HDMI
> displays.
>
> Correct I2C address comes from Lontium documentation and it is the one
> used on other out-of-tree LT8912B drivers [1].
>
> [1] https://github.com/boundarydevices/linux/blob/boundary-imx_5.10.x_2.0=
.0/drivers/video/lt8912.c#L296
>
> Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge")
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Acked-by: Adrien Grassein <adrien.grassein@gmail.com>
> ---
>
>  drivers/gpu/drm/bridge/lontium-lt8912b.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/b=
ridge/lontium-lt8912b.c
> index 6a4bb7422176..5968f4af190b 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c
> @@ -188,7 +188,7 @@ static int lt8912_write_lvds_config(struct lt8912 *lt=
)
>                 {0x03, 0xff},
>         };
>
> -       return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY=
_SIZE(seq));
> +       return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SI=
ZE(seq));
>  };
>
>  static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
> --
> 2.37.3
>