[PATCH] drm/bridge: ite66121: Register HPD interrupt handler only when 'client->irq > 0'

[Sui Jingfeng]

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@xxxxxxxxx>
---
 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