drm/vc4: crtc: Drop feed_txp from state

Accessing the crtc->state pointer from outside the modesetting context
is not allowed. We thus need to copy whatever we need from the KMS state
to our structure in order to access it.

In VC4, a number of users of that pointers have crept in over the years,
the first one being whether or not the downstream controller of the
pixelvalve is our writeback controller.

Fortunately for us, Since commit 39fcb280 ("drm/vc4: txp: Turn the
TXP into a CRTC of its own") this is no longer something that can change
from one commit to the other and is hardcoded.

Let's set this flag in struct vc4_crtc if we happen to be the TXP, and
drop the flag from our private state structure.

Link: https://lore.kernel.org/all/YWgteNaNeaS9uWDe@phenom.ffwll.local/
Link: https://lore.kernel.org/r/20211025141113.702757-2-maxime@cerno.tech
Fixes: 008095e0 ("drm/vc4: Add support for the transposer block")
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -723,7 +723,7 @@ static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc)
 	spin_lock_irqsave(&dev->event_lock, flags);
 	if (vc4_crtc->event &&
 	    (vc4_state->mm.start == HVS_READ(SCALER_DISPLACTX(chan)) ||
-	     vc4_state->feed_txp)) {
+	     vc4_crtc->feeds_txp)) {
 		drm_crtc_send_vblank_event(crtc, vc4_crtc->event);
 		vc4_crtc->event = NULL;
 		drm_crtc_vblank_put(crtc);
@@ -901,7 +901,6 @@ struct drm_crtc_state *vc4_crtc_duplicate_state(struct drm_crtc *crtc)
 		return NULL;
 
 	old_vc4_state = to_vc4_crtc_state(crtc->state);
-	vc4_state->feed_txp = old_vc4_state->feed_txp;
 	vc4_state->margins = old_vc4_state->margins;
 	vc4_state->assigned_channel = old_vc4_state->assigned_channel;
 

drivers/gpu/drm/vc4/vc4_drv.h

@@ -492,6 +492,11 @@ struct vc4_crtc {
 	struct drm_pending_vblank_event *event;
 
 	struct debugfs_regset32 regset;
+
+	/**
+	 * @feeds_txp: True if the CRTC feeds our writeback controller.
+	 */
+	bool feeds_txp;
 };
 
 static inline struct vc4_crtc *
@@ -521,7 +526,6 @@ struct vc4_crtc_state {
 	struct drm_crtc_state base;
 	/* Dlist area for this CRTC configuration. */
 	struct drm_mm_node mm;
-	bool feed_txp;
 	bool txp_armed;
 	unsigned int assigned_channel;
 

drivers/gpu/drm/vc4/vc4_hvs.c

@@ -375,7 +375,7 @@ static void vc4_hvs_update_dlist(struct drm_crtc *crtc)
 
 		spin_lock_irqsave(&dev->event_lock, flags);
 
-		if (!vc4_state->feed_txp || vc4_state->txp_armed) {
+		if (!vc4_crtc->feeds_txp || vc4_state->txp_armed) {
 			vc4_crtc->event = crtc->state->event;
 			crtc->state->event = NULL;
 		}
@@ -395,10 +395,9 @@ void vc4_hvs_atomic_enable(struct drm_crtc *crtc,
 {
 	struct drm_device *dev = crtc->dev;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
-	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(new_crtc_state);
 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
-	bool oneshot = vc4_state->feed_txp;
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	bool oneshot = vc4_crtc->feeds_txp;
 
 	vc4_hvs_update_dlist(crtc);
 	vc4_hvs_init_channel(vc4, crtc, mode, oneshot);

drivers/gpu/drm/vc4/vc4_kms.c

@@ -235,6 +235,7 @@ static void vc4_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 	unsigned int i;
 
 	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
+		struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 		struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc_state);
 		u32 dispctrl;
 		u32 dsp3_mux;
@@ -255,7 +256,7 @@ static void vc4_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 		 * TXP IP, and we need to disable the FIFO2 -> pixelvalve1
 		 * route.
 		 */
-		if (vc4_state->feed_txp)
+		if (vc4_crtc->feeds_txp)
 			dsp3_mux = VC4_SET_FIELD(3, SCALER_DISPCTRL_DSP3_MUX);
 		else
 			dsp3_mux = VC4_SET_FIELD(2, SCALER_DISPCTRL_DSP3_MUX);

drivers/gpu/drm/vc4/vc4_txp.c

@@ -391,7 +391,6 @@ static int vc4_txp_atomic_check(struct drm_crtc *crtc,
 {
 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
 									  crtc);
-	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc_state);
 	int ret;
 
 	ret = vc4_hvs_atomic_check(crtc, state);
@@ -399,7 +398,6 @@ static int vc4_txp_atomic_check(struct drm_crtc *crtc,
 		return ret;
 
 	crtc_state->no_vblank = true;
-	vc4_state->feed_txp = true;
 
 	return 0;
 }
@@ -482,6 +480,7 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 
 	vc4_crtc->pdev = pdev;
 	vc4_crtc->data = &vc4_txp_crtc_data;
+	vc4_crtc->feeds_txp = true;
 
 	txp->pdev = pdev;