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References: <20231207-kms-hdmi-connector-state-v5-0-6538e19d634d@kernel.org> <20231207-kms-hdmi-connector-state-v5-18-6538e19d634d@kernel.org>
In-Reply-To: <20231207-kms-hdmi-connector-state-v5-18-6538e19d634d@kernel.org>
From:   Dave Stevenson <dave.stevenson@raspberrypi.com>
Date:   Tue, 12 Dec 2023 11:40:26 +0000
Message-ID: <CAPY8ntBe9RfSjdnd5Smx23La5gQaR9WqY8ehXQyp=4D_11N55Q@mail.gmail.com>
Subject: Re: [PATCH v5 18/44] drm/vc4: hdmi: Create destroy state implementation
To:     Maxime Ripard <mripard@kernel.org>
Cc:     Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, Emma Anholt <emma@anholt.net>,
        Jonathan Corbet <corbet@lwn.net>,
        Sandy Huang <hjc@rock-chips.com>,
        =?UTF-8?Q?Heiko_St=C3=BCbner?= <heiko@sntech.de>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Samuel Holland <samuel@sholland.org>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, Hans Verkuil <hverkuil@xs4all.nl>,
        linux-rockchip@lists.infradead.org, linux-sunxi@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org
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On Thu, 7 Dec 2023 at 15:50, Maxime Ripard <mripard@kernel.org> wrote:
>
> Even though we were rolling our own custom state for the vc4 HDMI
> controller driver, we were still using the generic helper to destroy
> that state.
>
> It was mostly working since the underlying state is the first member of
> our state so the pointers are probably equal in all relevant cases, but
> it's still fragile so let's fix this properly.
>
> Signed-off-by: Maxime Ripard <mripard@kernel.org>

Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 25c9c71256d3..f05e2c95a60d 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -672,11 +672,21 @@ vc4_hdmi_connector_duplicate_state(struct drm_connector *connector)
>         return &new_state->base;
>  }
>
> +static void vc4_hdmi_connector_destroy_state(struct drm_connector *connector,
> +                                            struct drm_connector_state *state)
> +{
> +       struct vc4_hdmi_connector_state *vc4_state =
> +               conn_state_to_vc4_hdmi_conn_state(state);
> +
> +       __drm_atomic_helper_connector_destroy_state(state);
> +       kfree(vc4_state);
> +}
> +
>  static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {
>         .fill_modes = drm_helper_probe_single_connector_modes,
>         .reset = vc4_hdmi_connector_reset,
>         .atomic_duplicate_state = vc4_hdmi_connector_duplicate_state,
> -       .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +       .atomic_destroy_state = vc4_hdmi_connector_destroy_state,
>         .atomic_get_property = vc4_hdmi_connector_get_property,
>         .atomic_set_property = vc4_hdmi_connector_set_property,
>  };
>
> --
> 2.43.0
>