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From:   Pin-yen Lin <treapking@chromium.org>
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Cc:     Hsin-Yi Wang <hsinyi@chromium.org>,
        Pin-yen Lin <treapking@chromium.org>,
        dri-devel@lists.freedesktop.org, Marek Vasut <marex@denx.de>,
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        Thomas Zimmermann <tzimmermann@suse.de>,
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        Javier Martinez Canillas <javierm@redhat.com>,
        Lyude Paul <lyude@redhat.com>,
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        <nfraprado@collabora.com>, linux-kernel@vger.kernel.org
Subject: [PATCH v9 5/9] drm/bridge: anx7625: Check for Type-C during panel registration
Date:   Mon,  9 Jan 2023 16:40:57 +0800
Message-Id: <20230109084101.265664-6-treapking@chromium.org>
In-Reply-To: <20230109084101.265664-1-treapking@chromium.org>
References: <20230109084101.265664-1-treapking@chromium.org>
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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>

---

(no changes since v6)

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) {
-- 
2.39.0.314.g84b9a713c41-goog