On Mon, 25 Oct 2021 at 16:29, Maxime Ripard <maxime@xxxxxxxxxx> wrote:
>
> It turns out the encoder retrieval code, in addition to being
> unnecessarily complicated, has a bug when only the planes and crtcs are
> affected by a given atomic commit.
>
> Indeed, in such a case, either drm_atomic_get_old_connector_state or
> drm_atomic_get_new_connector_state will return NULL and thus our encoder
> retrieval code will not match on anything.
>
> We can however simplify the code by using drm_for_each_encoder_mask, the
> drm_crtc_state storing the encoders a given CRTC is connected to
> directly and without relying on any other state.
>
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/vc4/vc4_crtc.c | 30 +++++++++---------------------
> drivers/gpu/drm/vc4/vc4_drv.h | 4 +---
> 2 files changed, 10 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
> index e5c2e29a6f01..fbc1d4638650 100644
> --- a/drivers/gpu/drm/vc4/vc4_crtc.c
> +++ b/drivers/gpu/drm/vc4/vc4_crtc.c
> @@ -282,26 +282,14 @@ static u32 vc4_crtc_get_fifo_full_level_bits(struct vc4_crtc *vc4_crtc,
> * same CRTC.
> */
> struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
> - struct drm_atomic_state *state,
> - struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
> - struct drm_connector *connector))
> + struct drm_crtc_state *state)
> {
> - struct drm_connector *connector;
> - struct drm_connector_list_iter conn_iter;
> + struct drm_encoder *encoder;
>
> - drm_connector_list_iter_begin(crtc->dev, &conn_iter);
> - drm_for_each_connector_iter(connector, &conn_iter) {
> - struct drm_connector_state *conn_state = get_state(state, connector);
> + WARN_ON(hweight32(state->encoder_mask) > 1);
>
> - if (!conn_state)
> - continue;
> -
> - if (conn_state->crtc == crtc) {
> - drm_connector_list_iter_end(&conn_iter);
> - return connector->encoder;
> - }
> - }
> - drm_connector_list_iter_end(&conn_iter);
> + drm_for_each_encoder_mask(encoder, crtc->dev, state->encoder_mask)
> + return encoder;
>
> return NULL;
> }
> @@ -550,8 +538,7 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
> struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state,
> crtc);
> struct vc4_crtc_state *old_vc4_state = to_vc4_crtc_state(old_state);
> - struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, state,
> - drm_atomic_get_old_connector_state);
> + struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, old_state);
> struct drm_device *dev = crtc->dev;
>
> require_hvs_enabled(dev);
> @@ -578,10 +565,11 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
> static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
> struct drm_atomic_state *state)
> {
> + struct drm_crtc_state *new_state = drm_atomic_get_new_crtc_state(state,
> + crtc);
> struct drm_device *dev = crtc->dev;
> struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
> - struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, state,
> - drm_atomic_get_new_connector_state);
> + struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, new_state);
> struct vc4_encoder *vc4_encoder = to_vc4_encoder(encoder);
>
> require_hvs_enabled(dev);
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
> index f5e678491502..60826aca9e5b 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.h
> +++ b/drivers/gpu/drm/vc4/vc4_drv.h
> @@ -545,9 +545,7 @@ vc4_crtc_to_vc4_pv_data(const struct vc4_crtc *crtc)
> }
>
> struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
> - struct drm_atomic_state *state,
> - struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
> - struct drm_connector *connector));
> + struct drm_crtc_state *state);
>
> struct vc4_crtc_state {
> struct drm_crtc_state base;
> --
> 2.31.1
>
