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From:   Kalyan Thota <quic_kalyant@quicinc.com>
To:     dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        freedreno@lists.freedesktop.org, devicetree@vger.kernel.org
Cc:     Kalyan Thota <quic_kalyant@quicinc.com>,
        linux-kernel@vger.kernel.org, robdclark@chromium.org,
        dianders@chromium.org, swboyd@chromium.org,
        quic_vpolimer@quicinc.com, dmitry.baryshkov@linaro.org,
        quic_abhinavk@quicinc.com
Subject: [PATCH v2 1/3] drm/msm/disp/dpu1: pin 1 crtc to 1 encoder
Date:   Wed, 16 Nov 2022 06:30:38 -0800
Message-Id: <1668609040-2549-2-git-send-email-quic_kalyant@quicinc.com>
In-Reply-To: <1668609040-2549-1-git-send-email-quic_kalyant@quicinc.com>
References: <1668609040-2549-1-git-send-email-quic_kalyant@quicinc.com>
Precedence: bulk

Pin each crtc with one encoder. This arrangement will
disallow crtc switching between encoders and also will
facilitate to advertise certain features on crtc based
on encoder type.

Changes in v1:
- use drm_for_each_encoder macro while iterating through
  encoder list (Dmitry)

Changes in v2:
- make sure no encoder miss to have a crtc (Dmitry)
- revisit various factors in deciding the crtc count
  such as num_mixers, num_sspp (Dmitry)

Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index 7a5fabc..4784db8 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -763,7 +763,7 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
 	drm_for_each_encoder(encoder, dev)
 		num_encoders++;
 
-	max_crtc_count = min(catalog->mixer_count, num_encoders);
+	max_crtc_count = num_encoders;
 
 	/* Create the planes, keeping track of one primary/cursor per crtc */
 	for (i = 0; i < catalog->sspp_count; i++) {
@@ -795,22 +795,25 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
 			primary_planes[primary_planes_idx++] = plane;
 	}
 
-	max_crtc_count = min(max_crtc_count, primary_planes_idx);
+	/*
+	 * All the platforms should have at least 1 primary plane for an
+	 * encoder. The below warn should help in setting up the catalog
+	 */
+	WARN_ON(num_encoders > primary_planes_idx);
 
 	/* Create one CRTC per encoder */
-	for (i = 0; i < max_crtc_count; i++) {
+	i = 0;
+	drm_for_each_encoder(encoder, dev) {
 		crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i]);
 		if (IS_ERR(crtc)) {
 			ret = PTR_ERR(crtc);
 			return ret;
 		}
 		priv->crtcs[priv->num_crtcs++] = crtc;
+		encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
+		i++;
 	}
 
-	/* All CRTCs are compatible with all encoders */
-	drm_for_each_encoder(encoder, dev)
-		encoder->possible_crtcs = (1 << priv->num_crtcs) - 1;
-
 	return 0;
 }
 
-- 
2.7.4