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Date:   Sun, 3 Dec 2023 16:24:41 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc:     dri-devel@lists.freedesktop.org,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        freedreno@lists.freedesktop.org, quic_jesszhan@quicinc.com,
        quic_parellan@quicinc.com, andersson@kernel.org,
        jani.nikula@linux.intel.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm: improve the documentation of connector hpd ops
Message-ID: <20231203142441.GA26644@pendragon.ideasonboard.com>
References: <20230920201358.27597-1-quic_abhinavk@quicinc.com>
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In-Reply-To: <20230920201358.27597-1-quic_abhinavk@quicinc.com>
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Hi Abhinav,

Thank you for the patch (and thank to Dmitry for pinging me on IRC, this
patch got burried in my inbox).

On Wed, Sep 20, 2023 at 01:13:58PM -0700, Abhinav Kumar wrote:
> While making the changes in [1], it was noted that the documentation
> of the enable_hpd() and disable_hpd() does not make it clear that
> these ops should not try to do hpd state maintenance and should only
> attempt to enable/disable hpd related hardware for the connector.

s/attempt to //

> 
> The state management of these calls to make sure these calls are
> balanced is handled by the DRM core and we should keep it that way
> to minimize the overhead in the drivers which implement these ops.
> 
> [1]: https://patchwork.freedesktop.org/patch/558387/
> 

You could add a

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  include/drm/drm_modeset_helper_vtables.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
> index e3c3ac615909..a33cf7488737 100644
> --- a/include/drm/drm_modeset_helper_vtables.h
> +++ b/include/drm/drm_modeset_helper_vtables.h
> @@ -1154,6 +1154,11 @@ struct drm_connector_helper_funcs {
>  	 * This operation is optional.
>  	 *
>  	 * This callback is used by the drm_kms_helper_poll_enable() helpers.
> +	 *
> +	 * This operation does not need to perform any hpd state tracking as
> +	 * the DRM core handles that maintenance and ensures the calls to enable
> +	 * and disable hpd are balanced.
> +	 *
>  	 */
>  	void (*enable_hpd)(struct drm_connector *connector);
>  
> @@ -1165,6 +1170,11 @@ struct drm_connector_helper_funcs {
>  	 * This operation is optional.
>  	 *
>  	 * This callback is used by the drm_kms_helper_poll_disable() helpers.
> +	 *
> +	 * This operation does not need to perform any hpd state tracking as
> +	 * the DRM core handles that maintenance and ensures the calls to enable
> +	 * and disable hpd are balanced.
> +	 *
>  	 */
>  	void (*disable_hpd)(struct drm_connector *connector);
>  };

-- 
Regards,

Laurent Pinchart