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From: Luca Ceresoli <luca.ceresoli@bootlin.com>
To: Andrzej Hajda <andrzej.hajda@intel.com>,
	 Neil Armstrong <neil.armstrong@linaro.org>,
	Robert Foss <rfoss@kernel.org>,
	 Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
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	 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	 Maxime Ripard <mripard@kernel.org>,
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	 David Airlie <airlied@gmail.com>,
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	 Jonathan Corbet <corbet@lwn.net>,
	Alexey Brodkin <abrodkin@synopsys.com>,
	 Phong LE <ple@baylibre.com>, Liu Ying <victor.liu@nxp.com>,
	 Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
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	 Chun-Kuang Hu <chunkuang.hu@kernel.org>,
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	 Inki Dae <inki.dae@samsung.com>,
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	 Kyungmin Park <kyungmin.park@samsung.com>,
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	 Alim Akhtar <alim.akhtar@samsung.com>
Cc: Hui Pu <Hui.Pu@gehealthcare.com>,
	 Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	 Louis Chauvet <louis.chauvet@bootlin.com>,
	dri-devel@lists.freedesktop.org,  linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org,  imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org,
	 linux-renesas-soc@vger.kernel.org,
	linux-amlogic@lists.infradead.org,
	 linux-mediatek@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org,
	 Luca Ceresoli <luca.ceresoli@bootlin.com>
Subject: [PATCH v2 24/26] drm/bridge: imx8qxp-pixel-link: simplify logic to find next bridge
Date: Fri, 28 Nov 2025 17:50:34 +0100	[thread overview]
Message-ID: <20251128-drm-bridge-alloc-getput-drm_of_find_bridge-v2-24-88f8a107eca2@bootlin.com> (raw)
In-Reply-To: <20251128-drm-bridge-alloc-getput-drm_of_find_bridge-v2-0-88f8a107eca2@bootlin.com>

imx8qxp_pixel_link_find_next_bridge() uses a sophisticated logic to find
the preferred next bridge, using an array with two supporting index
variables. This is more sophisticated than required because we only ever
need a pointer to the "current" bridge and to the "best so far" bridge.

Additionally this logic is going to make the addition of proper refcounting
quite complex.

Rewrite the logic using two drm_bridge pointers, which is by itself
slightly simpler and is a preparation step for introducing bridge
refcounting in a later commit.

Also reword a comment to make it clearer.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

---

Cc: Liu Ying <victor.liu@nxp.com>
---
 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
index e5943506981d..53016f0d53a0 100644
--- a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
@@ -261,12 +261,10 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 {
 	struct device_node *np = pl->dev->of_node;
 	struct device_node *port, *remote;
-	struct drm_bridge *next_bridge[PL_MAX_NEXT_BRIDGES];
+	struct drm_bridge *selected_bridge = NULL;
 	u32 port_id;
 	bool found_port = false;
-	int reg, ep_cnt = 0;
-	/* select the first next bridge by default */
-	int bridge_sel = 0;
+	int reg;
 
 	for (port_id = 1; port_id <= PL_MAX_MST_ADDR + 1; port_id++) {
 		port = of_graph_get_port_by_id(np, port_id);
@@ -300,24 +298,25 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 			continue;
 		}
 
-		next_bridge[ep_cnt] = of_drm_find_bridge(remote);
-		if (!next_bridge[ep_cnt]) {
+		struct drm_bridge *next_bridge = of_drm_find_bridge(remote);
+		if (!next_bridge) {
 			of_node_put(remote);
 			return ERR_PTR(-EPROBE_DEFER);
 		}
 
-		/* specially select the next bridge with companion PXL2DPI */
-		if (of_property_present(remote, "fsl,companion-pxl2dpi"))
-			bridge_sel = ep_cnt;
-
-		ep_cnt++;
+		/*
+		 * Select the next bridge with companion PXL2DPI if
+		 * present, otherwise default to the first bridge
+		 */
+		if (!selected_bridge || of_property_present(remote, "fsl,companion-pxl2dpi"))
+			selected_bridge = next_bridge;
 
 		of_node_put(remote);
 	}
 
 	pl->mst_addr = port_id - 1;
 
-	return next_bridge[bridge_sel];
+	return selected_bridge;
 }
 
 static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)

-- 
2.51.1


  parent reply	other threads:[~2025-11-28 16:55 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-28 16:50 [PATCH v2 00/26] drm/bridge: add drm_of_find_bridge(), deprecate of_drm_find_bridge() Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 01/26] drm/bridge: add of_drm_get_bridge() Luca Ceresoli
2025-12-15 14:29   ` Maxime Ripard
2025-11-28 16:50 ` [PATCH v2 02/26] drm/bridge: deprecate of_drm_find_bridge() Luca Ceresoli
2025-12-15 14:29   ` Maxime Ripard
2025-11-28 16:50 ` [PATCH v2 03/26] drm/todo: add entry about converting to of_drm_get_bridge() Luca Ceresoli
2025-12-15 15:15   ` Maxime Ripard
2025-11-28 16:50 ` [PATCH v2 04/26] drm/bridge: make of_drm_find_bridge() a wrapper of of_drm_get_bridge() Luca Ceresoli
2025-11-28 21:50   ` Randy Dunlap
2025-11-28 16:50 ` [PATCH v2 05/26] drm/arcpgu: convert to of_drm_get_bridge() Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 06/26] drm/bridge: add devm_of_drm_get_bridge Luca Ceresoli
2025-12-15 15:21   ` Maxime Ripard
2025-11-28 16:50 ` [PATCH v2 07/26] drm/bridge: ite-it66121: use devm_of_drm_get_bridge() to put the next bridge Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 08/26] drm/bridge: imx8qxp-pixel-combiner: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 09/26] drm/bridge: simple-bridge: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 10/26] drm/bridge: tpd12s015: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 11/26] drm/bridge: thc63lvd1024: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 12/26] drm/bridge: imx8qxp-pxl2dpi: use devm_of_drm_get_bridge() to put the next and companion bridges Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 13/26] drm/bridge: lt8912b: use devm_of_drm_get_bridge() to put the hdmi bridge Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 14/26] drm/bridge: tfp410: use devm_of_drm_get_bridge() to put the next bridge Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 15/26] drm/bridge: imx8qxp-ldb: use devm_of_drm_get_bridge() to put the companion bridge Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 16/26] drm/rcar-du: lvds: use devm_of_drm_get_bridge() to put the next bridge Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 17/26] drm/meson: encoder_*: " Luca Ceresoli
2025-11-30 13:09   ` Martin Blumenstingl
2025-12-16 12:46     ` Luca Ceresoli
2025-12-17  0:01       ` Martin Blumenstingl
2025-12-17  8:15         ` Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 18/26] drm/bridge: sii902x: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 19/26] drm/mediatek: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 20/26] drm/kmb: dsi: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 21/26] drm/imx/ipuv3: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 22/26] drm/exynos: hdmi: " Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 23/26] drm/bridge: dw-hdmi: " Luca Ceresoli
2025-11-28 16:50 ` Luca Ceresoli [this message]
2025-11-28 16:50 ` [PATCH v2 25/26] drm/bridge: imx8qxp-pixel-link: simplify freeing of the remote device_node Luca Ceresoli
2025-11-28 16:50 ` [PATCH v2 26/26] drm/bridge: imx8qxp-pixel-link: convert to of_drm_get_bridge() Luca Ceresoli

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