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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 v4 1/3] drm/msm/disp/dpu1: pin 1 crtc to 1 encoder
Date:   Mon, 21 Nov 2022 01:08:13 -0800
Message-Id: <1669021695-4397-2-git-send-email-quic_kalyant@quicinc.com>
In-Reply-To: <1669021695-4397-1-git-send-email-quic_kalyant@quicinc.com>
References: <1669021695-4397-1-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)

Changes in v3:
- none

Changes in v4:
- use max_crtc_count instead of num_encoders in WARN (Dmitry)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 18 +++++++++++-------
 1 file changed, 11 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..d967eef 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -747,6 +747,7 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
 
 	int primary_planes_idx = 0, cursor_planes_idx = 0, i, ret;
 	int max_crtc_count;
+
 	dev = dpu_kms->dev;
 	priv = dev->dev_private;
 	catalog = dpu_kms->catalog;
@@ -763,7 +764,7 @@ 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 +796,25 @@ 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 a
+	 * crtc. The below warn should help in setting up the catalog
+	 */
+	WARN_ON(max_crtc_count > 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