linux-kernel - [PATCH] drm/bridge: ite66121: Register HPD interrupt handler only when 'client->irq

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Message-Id: <20240316160536.1051513-1-sui.jingfeng@linux.dev>
Date: Sun, 17 Mar 2024 00:05:36 +0800
From: Sui Jingfeng <sui.jingfeng@...ux.dev>
To: Phong LE <ple@...libre.com>
Cc: Neil Armstrong <neil.armstrong@...aro.org>,
	Andrzej Hajda <andrzej.hajda@...el.com>,
	Robert Foss <rfoss@...nel.org>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	Jonas Karlman <jonas@...boo.se>,
	Jernej Skrabec <jernej.skrabec@...il.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Sui Jingfeng <sui.jingfeng@...ux.dev>
Subject: [PATCH] drm/bridge: ite66121: Register HPD interrupt handler only when 'client->irq > 0'

If a specific design doesn't wire IT66121's interrupt signal output pin up
to the display controller side, then we should not register the interrupt
handler. Such a decision is valid usage, as we can fall back to polling
mode. So, don't make the assumption that a specific board always supports
HPD. Carry out a sanity check on 'client->irq' before using it, fall back
to polling mode if client->irq < 0 is true. Such a design increases the
overall flexibility.

Signed-off-by: Sui Jingfeng <sui.jingfeng@...ux.dev>
---
 drivers/gpu/drm/bridge/ite-it66121.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index 1c3433b5e366..052884058644 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -1586,13 +1586,18 @@ static int it66121_probe(struct i2c_client *client)
 	ctx->bridge.funcs = &it66121_bridge_funcs;
 	ctx->bridge.of_node = dev->of_node;
 	ctx->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
-	ctx->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
-
-	ret = devm_request_threaded_irq(dev, client->irq, NULL,	it66121_irq_threaded_handler,
-					IRQF_ONESHOT, dev_name(dev), ctx);
-	if (ret < 0) {
-		dev_err(dev, "Failed to request irq %d:%d\n", client->irq, ret);
-		return ret;
+	ctx->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID;
+	if (client->irq > 0) {
+		ctx->bridge.ops |= DRM_BRIDGE_OP_HPD;
+
+		ret = devm_request_threaded_irq(dev, client->irq, NULL,
+						it66121_irq_threaded_handler,
+						IRQF_ONESHOT, dev_name(dev),
+						ctx);
+		if (ret < 0) {
+			dev_err(dev, "Failed to request irq %d:%d\n", client->irq, ret);
+			return ret;
+		}
 	}
 
 	it66121_audio_codec_init(ctx, dev);
-- 
2.34.1