linux-kernel - Re: [PATCH v5 08/17] drm/meson: fix unbind path if HDMI fails to bind

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Date:   Wed, 31 May 2023 11:19:32 +0200
From:   Nicolas Belin <nbelin@...libre.com>
To:     Neil Armstrong <neil.armstrong@...aro.org>
Cc:     Jerome Brunet <jbrunet@...libre.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Kevin Hilman <khilman@...libre.com>,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Kishon Vijay Abraham I <kishon@...nel.org>,
        Sam Ravnborg <sam@...nborg.org>,
        "Lukas F. Hartmann" <lukas@...re.com>,
        linux-amlogic@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-phy@...ts.infradead.org
Subject: Re: [PATCH v5 08/17] drm/meson: fix unbind path if HDMI fails to bind

Le mar. 30 mai 2023 à 09:38, Neil Armstrong
<neil.armstrong@...aro.org> a écrit :
>
> If the case the HDMI controller fails to bind, we try to unbind
> all components before calling drm_dev_put() which makes drm_bridge_detach()
> crash because unbinding the HDMI controller frees the bridge memory.
>
> The solution is the unbind all components at the end like in the remove
> path.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@...aro.org>
> ---
>  drivers/gpu/drm/meson/meson_drv.c | 23 ++++++++++++++---------
>  1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index ca6d1e59e5d9..e060279dc80a 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -316,32 +316,34 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>                 goto exit_afbcd;
>
>         if (has_components) {
> -               ret = component_bind_all(drm->dev, drm);
> +               ret = component_bind_all(dev, drm);
>                 if (ret) {
>                         dev_err(drm->dev, "Couldn't bind all components\n");
> +                       /* Do not try to unbind */
> +                       has_components = false;
>                         goto exit_afbcd;
>                 }
>         }
>
>         ret = meson_encoder_hdmi_init(priv);
>         if (ret)
> -               goto unbind_all;
> +               goto exit_afbcd;
>
>         ret = meson_plane_create(priv);
>         if (ret)
> -               goto unbind_all;
> +               goto exit_afbcd;
>
>         ret = meson_overlay_create(priv);
>         if (ret)
> -               goto unbind_all;
> +               goto exit_afbcd;
>
>         ret = meson_crtc_create(priv);
>         if (ret)
> -               goto unbind_all;
> +               goto exit_afbcd;
>
>         ret = request_irq(priv->vsync_irq, meson_irq, 0, drm->driver->name, drm);
>         if (ret)
> -               goto unbind_all;
> +               goto exit_afbcd;
>
>         drm_mode_config_reset(drm);
>
> @@ -359,15 +361,18 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>
>  uninstall_irq:
>         free_irq(priv->vsync_irq, drm);
> -unbind_all:
> -       if (has_components)
> -               component_unbind_all(drm->dev, drm);
>  exit_afbcd:
>         if (priv->afbcd.ops)
>                 priv->afbcd.ops->exit(priv);
>  free_drm:
>         drm_dev_put(drm);
>
> +       meson_encoder_hdmi_remove(priv);
> +       meson_encoder_cvbs_remove(priv);
> +
> +       if (has_components)
> +               component_unbind_all(dev, drm);
> +
>         return ret;
>  }
>
>
> --
> 2.34.1
>

Works fine on a Khadas VIM3 using a TS050 panel,
Thanks

Reviewed-by: Nicolas Belin <nbelin@...libre.com>
Tested-by: Nicolas Belin <nbelin@...libre.com>