[PATCH v7 05/10] drm/vc4: crtc: Rework the encoder retrieval code (again)

From: Maxime Ripard
Date: Thu Aug 19 2021 - 05:51:47 EST


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>
---
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 93d2413d0842..c88ce31ec90f 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -280,26 +280,14 @@ 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;
}
@@ -533,8 +521,7 @@ 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);
@@ -561,10 +548,11 @@ 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 0865f05822e0..220c5e81ba2c 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -518,9 +518,7 @@ 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