From:   Pin-yen Lin <treapking@chromium.org>
To:     Andrzej Hajda <andrzej.hajda@intel.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Robert Foss <robert.foss@linaro.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Daniel Scally <djrscally@gmail.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        Prashant Malani <pmalani@chromium.org>,
        Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>
Cc:     linux-kernel@vger.kernel.org,
        =?UTF-8?q?N=C3=ADcolas=20F=20=2E=20R=20=2E=20A=20=2E=20Prado?= 
        <nfraprado@collabora.com>, Hsin-Yi Wang <hsinyi@chromium.org>,
        devicetree@vger.kernel.org, Pin-yen Lin <treapking@chromium.org>,
        Allen Chen <allen.chen@ite.com.tw>,
        Lyude Paul <lyude@redhat.com>, linux-acpi@vger.kernel.org,
        dri-devel@lists.freedesktop.org, Marek Vasut <marex@denx.de>,
        Xin Ji <xji@analogixsemi.com>,
        Stephen Boyd <swboyd@chromium.org>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Javier Martinez Canillas <javierm@redhat.com>,
        chrome-platform@lists.linux.dev, Chen-Yu Tsai <wenst@chromium.org>,
        =?UTF-8?q?Jos=C3=A9=20Exp=C3=B3sito?= <jose.exposito89@gmail.com>
Subject: [PATCH v11 5/9] drm/bridge: anx7625: Check for Type-C during panel registration
Date:   Sat,  4 Feb 2023 21:30:36 +0800
Message-Id: <20230204133040.1236799-6-treapking@chromium.org>
In-Reply-To: <20230204133040.1236799-1-treapking@chromium.org>
References: <20230204133040.1236799-1-treapking@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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The output port endpoints can be connected to USB-C connectors.
Running drm_of_find_panel_or_bridge() with such endpoints leads to
a continuous return value of -EPROBE_DEFER, even though there is
no panel present.

To avoid this, check for the existence of a "mode-switch" property in
the port endpoint, and skip panel registration completely if so.

Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>

---

(no changes since v10)

Changes in v10:
- Collected Reviewed-by and Tested-by tags

Changes in v6:
- New in v6

 drivers/gpu/drm/bridge/analogix/anx7625.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index b375887e655d..1cf242130b91 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1649,7 +1649,7 @@ static int anx7625_get_swing_setting(struct device *dev,
 static int anx7625_parse_dt(struct device *dev,
 			    struct anx7625_platform_data *pdata)
 {
-	struct device_node *np = dev->of_node, *ep0;
+	struct device_node *np = dev->of_node, *ep0, *sw;
 	int bus_type, mipi_lanes;
 
 	anx7625_get_swing_setting(dev, pdata);
@@ -1688,6 +1688,17 @@ static int anx7625_parse_dt(struct device *dev,
 	if (of_property_read_bool(np, "analogix,audio-enable"))
 		pdata->audio_en = 1;
 
+	/*
+	 * Don't bother finding a panel if a Type-C `mode-switch` property is
+	 * present in one of the endpoints.
+	 */
+	for_each_endpoint_of_node(np, sw) {
+		if (of_property_read_bool(sw, "mode-switch")) {
+			of_node_put(sw);
+			return 0;
+		}
+	}
+
 	pdata->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);
 	if (IS_ERR(pdata->panel_bridge)) {
 		if (PTR_ERR(pdata->panel_bridge) == -ENODEV) {
-- 
2.39.1.519.gcb327c4b5f-goog