drm/msm/dpu: check for overflow in _dpu_crtc_setup_lm_bounds()

Make _dpu_crtc_setup_lm_bounds() check that CRTC width is not
overflowing LM requirements. Rename the function accordingly.

Fixes: 25fdd593 ("drm/msm: Add SDM845 DPU support")
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Tested-by: Abhinav Kumar <quic_abhinavk@quicinc.com> # sc7280
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/612237/
Link: https://lore.kernel.org/r/20240903-dpu-mode-config-width-v6-3-617e1ecc4b7a@linaro.orgSigned-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c

@@ -711,12 +711,13 @@ void dpu_crtc_complete_commit(struct drm_crtc *crtc)
 	_dpu_crtc_complete_flip(crtc);
 }
 
-static void _dpu_crtc_setup_lm_bounds(struct drm_crtc *crtc,
+static int _dpu_crtc_check_and_setup_lm_bounds(struct drm_crtc *crtc,
 		struct drm_crtc_state *state)
 {
 	struct dpu_crtc_state *cstate = to_dpu_crtc_state(state);
 	struct drm_display_mode *adj_mode = &state->adjusted_mode;
 	u32 crtc_split_width = adj_mode->hdisplay / cstate->num_mixers;
+	struct dpu_kms *dpu_kms = _dpu_crtc_get_kms(crtc);
 	int i;
 
 	for (i = 0; i < cstate->num_mixers; i++) {
@@ -727,7 +728,12 @@ static void _dpu_crtc_setup_lm_bounds(struct drm_crtc *crtc,
 		r->y2 = adj_mode->vdisplay;
 
 		trace_dpu_crtc_setup_lm_bounds(DRMID(crtc), i, r);
+
+		if (drm_rect_width(r) > dpu_kms->catalog->caps->max_mixer_width)
+			return -E2BIG;
 	}
+
+	return 0;
 }
 
 static void _dpu_crtc_get_pcc_coeff(struct drm_crtc_state *state,
@@ -803,7 +809,7 @@ static void dpu_crtc_atomic_begin(struct drm_crtc *crtc,
 
 	DRM_DEBUG_ATOMIC("crtc%d\n", crtc->base.id);
 
-	_dpu_crtc_setup_lm_bounds(crtc, crtc->state);
+	_dpu_crtc_check_and_setup_lm_bounds(crtc, crtc->state);
 
 	/* encoder will trigger pending mask now */
 	drm_for_each_encoder_mask(encoder, crtc->dev, crtc->state->encoder_mask)
@@ -1189,8 +1195,11 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crtc,
 	if (crtc_state->active_changed)
 		crtc_state->mode_changed = true;
 
-	if (cstate->num_mixers)
-		_dpu_crtc_setup_lm_bounds(crtc, crtc_state);
+	if (cstate->num_mixers) {
+		rc = _dpu_crtc_check_and_setup_lm_bounds(crtc, crtc_state);
+		if (rc)
+			return rc;
+	}
 
 	/* FIXME: move this to dpu_plane_atomic_check? */
 	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, crtc_state) {