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From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date:   Tue, 22 Feb 2022 05:30:30 +0300
Message-ID: <CAA8EJpo8AnGhskdHPSxeN4Z1+KCKhrwprNF1x27Kr9qOG3CT8A@mail.gmail.com>
Subject: Re: [PATCH v2 2/4] drm/bridge: use atomic enable/disable for bridge callbacks
To:     Vinod Polimera <quic_vpolimer@quicinc.com>
Cc:     dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, agross@kernel.org,
        bjorn.andersson@linaro.org, robh+dt@kernel.org,
        robdclark@gmail.com, seanpaul@chromium.org, swboyd@chromium.org,
        dianders@chromium.org, krzysztof.kozlowski@canonical.com,
        thierry.reding@gmail.com, sam@ravnborg.org, airlied@linux.ie,
        daniel@ffwll.ch, quic_kalyant@quicinc.com,
        quic_sbillaka@quicinc.com, quic_vproddut@quicinc.com
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Precedence: bulk

On Mon, 21 Feb 2022 at 17:52, Vinod Polimera <quic_vpolimer@quicinc.com> wrote:
>
> Use atomic enable/disable for bridge callbacks to access certain
> states like self-refresh.
>
> This change avoids panel prepare/unprepare based on self-refresh
> state.

Please split this into two patches:
- change to atomic_* callbacks
- introduction of PSR support.

>
> Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
> Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
> Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>
>
> Changes in V2:
> - As per review suggestion by Dmitry.
> ---
>  drivers/gpu/drm/bridge/panel.c | 102 +++++++++++++++++++++++++++++++++++++----
>  1 file changed, 94 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
> index b32295a..5c7dc82 100644
> --- a/drivers/gpu/drm/bridge/panel.c
> +++ b/drivers/gpu/drm/bridge/panel.c
> @@ -41,6 +41,40 @@ static int panel_bridge_connector_get_modes(struct drm_connector *connector)
>         return drm_panel_get_modes(panel_bridge->panel, connector);
>  }
>
> +static struct drm_crtc *bridge_drm_get_old_connector_crtc(struct drm_encoder *encoder,
> +                                               struct drm_atomic_state *state)
> +{
> +       struct drm_connector *connector;
> +       struct drm_connector_state *conn_state;
> +
> +       connector = drm_atomic_get_old_connector_for_encoder(state, encoder);
> +       if (!connector)
> +               return NULL;
> +
> +       conn_state = drm_atomic_get_old_connector_state(state, connector);
> +       if (!conn_state)
> +               return NULL;
> +
> +       return conn_state->crtc;
> +}
> +
> +static struct drm_crtc *bridge_drm_get_new_connector_crtc(struct drm_encoder *encoder,
> +                                               struct drm_atomic_state *state)
> +{
> +       struct drm_connector *connector;
> +       struct drm_connector_state *conn_state;
> +
> +       connector = drm_atomic_get_new_connector_for_encoder(state, encoder);
> +       if (!connector)
> +               return NULL;
> +
> +       conn_state = drm_atomic_get_new_connector_state(state, connector);
> +       if (!conn_state)
> +               return NULL;
> +
> +       return conn_state->crtc;
> +}
> +
>  static const struct drm_connector_helper_funcs
>  panel_bridge_connector_helper_funcs = {
>         .get_modes = panel_bridge_connector_get_modes,
> @@ -102,30 +136,82 @@ static void panel_bridge_detach(struct drm_bridge *bridge)
>                 drm_connector_cleanup(connector);
>  }
>
> -static void panel_bridge_pre_enable(struct drm_bridge *bridge)
> +static void panel_bridge_pre_enable(struct drm_bridge *bridge,
> +               struct drm_bridge_state *old_bridge_state)
>  {
>         struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
> +       struct drm_atomic_state *old_state = old_bridge_state->base.state;
> +       struct drm_encoder *encoder = bridge->encoder;
> +       struct drm_crtc *crtc;
> +       struct drm_crtc_state *old_crtc_state;
> +
> +       crtc = bridge_drm_get_new_connector_crtc(encoder, old_state);
> +       if (!crtc)
> +               return;
> +
> +       old_crtc_state = drm_atomic_get_old_crtc_state(old_state, crtc);
> +       if (old_crtc_state && old_crtc_state->self_refresh_active)
> +               return;
>
>         drm_panel_prepare(panel_bridge->panel);
>  }
>
> -static void panel_bridge_enable(struct drm_bridge *bridge)
> +static void panel_bridge_enable(struct drm_bridge *bridge,
> +               struct drm_bridge_state *old_bridge_state)
>  {
>         struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
> +       struct drm_atomic_state *old_state = old_bridge_state->base.state;
> +       struct drm_encoder *encoder = bridge->encoder;
> +       struct drm_crtc *crtc;
> +       struct drm_crtc_state *old_crtc_state;
> +
> +       crtc = bridge_drm_get_new_connector_crtc(encoder, old_state);
> +       if (!crtc)
> +               return;
> +
> +       old_crtc_state = drm_atomic_get_old_crtc_state(old_state, crtc);
> +       if (old_crtc_state && old_crtc_state->self_refresh_active)
> +               return;
>
>         drm_panel_enable(panel_bridge->panel);
>  }
>
> -static void panel_bridge_disable(struct drm_bridge *bridge)
> +static void panel_bridge_disable(struct drm_bridge *bridge,
> +               struct drm_bridge_state *old_bridge_state)
>  {
>         struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
> +       struct drm_atomic_state *old_state = old_bridge_state->base.state;
> +       struct drm_encoder *encoder = bridge->encoder;
> +       struct drm_crtc *crtc;
> +       struct drm_crtc_state *new_crtc_state;
> +
> +       crtc = bridge_drm_get_old_connector_crtc(encoder, old_state);
> +       if (!crtc)
> +               return;
> +
> +       new_crtc_state = drm_atomic_get_new_crtc_state(old_state, crtc);
> +       if (new_crtc_state && new_crtc_state->self_refresh_active)
> +               return;
>
>         drm_panel_disable(panel_bridge->panel);
>  }
>
> -static void panel_bridge_post_disable(struct drm_bridge *bridge)
> +static void panel_bridge_post_disable(struct drm_bridge *bridge,
> +               struct drm_bridge_state *old_bridge_state)
>  {
>         struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
> +       struct drm_atomic_state *old_state = old_bridge_state->base.state;
> +       struct drm_encoder *encoder = bridge->encoder;
> +       struct drm_crtc *crtc;
> +       struct drm_crtc_state *new_crtc_state;
> +
> +       crtc = bridge_drm_get_old_connector_crtc(encoder, old_state);
> +       if (!crtc)
> +               return;
> +
> +       new_crtc_state = drm_atomic_get_new_crtc_state(old_state, crtc);
> +       if (new_crtc_state && new_crtc_state->self_refresh_active)
> +               return;
>
>         drm_panel_unprepare(panel_bridge->panel);
>  }
> @@ -141,10 +227,10 @@ static int panel_bridge_get_modes(struct drm_bridge *bridge,
>  static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
>         .attach = panel_bridge_attach,
>         .detach = panel_bridge_detach,
> -       .pre_enable = panel_bridge_pre_enable,
> -       .enable = panel_bridge_enable,
> -       .disable = panel_bridge_disable,
> -       .post_disable = panel_bridge_post_disable,
> +       .atomic_pre_enable = panel_bridge_pre_enable,
> +       .atomic_enable = panel_bridge_enable,
> +       .atomic_disable = panel_bridge_disable,
> +       .atomic_post_disable = panel_bridge_post_disable,

Please change callback names to reflect that we are using atomic_ interfaces.

>         .get_modes = panel_bridge_get_modes,
>         .atomic_reset = drm_atomic_helper_bridge_reset,
>         .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> --
> 2.7.4
>


-- 
With best wishes
Dmitry