linux-kernel - [PATCH] drm/bridge: it6505: Disable IRQ when powered off

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Message-ID: <20240719110623.1850021-1-treapking@chromium.org>
Date: Fri, 19 Jul 2024 19:05:36 +0800
From: Pin-yen Lin <treapking@...omium.org>
To: Andrzej Hajda <andrzej.hajda@...el.com>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Robert Foss <rfoss@...nel.org>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	Jonas Karlman <jonas@...boo.se>,
	Jernej Skrabec <jernej.skrabec@...il.com>
Cc: Chen-Yu Tsai <wenst@...omium.org>,
	Kuro Chung <kuro.chung@....com.tw>,
	linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	Pin-yen Lin <treapking@...omium.org>
Subject: [PATCH] drm/bridge: it6505: Disable IRQ when powered off

When the bridge is powered off, disable the IRQ until the next power on
to workaround an interrupt storm on some badly-designed hardware.

Signed-off-by: Pin-yen Lin <treapking@...omium.org>
---

 drivers/gpu/drm/bridge/ite-it6505.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 1e1c06fdf206..87b8545fccc0 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -460,6 +460,8 @@ struct it6505 {
 	bool enable_drv_hold;
 
 	const struct drm_edid *cached_edid;
+
+	int irq;
 };
 
 struct it6505_step_train_para {
@@ -2624,6 +2626,8 @@ static int it6505_poweron(struct it6505 *it6505)
 	it6505_init(it6505);
 	it6505_lane_off(it6505);
 
+	enable_irq(it6505->irq);
+
 	return 0;
 }
 
@@ -2640,6 +2644,8 @@ static int it6505_poweroff(struct it6505 *it6505)
 		return 0;
 	}
 
+	disable_irq_nosync(it6505->irq);
+
 	if (pdata->gpiod_reset)
 		gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
 
@@ -3389,7 +3395,7 @@ static int it6505_i2c_probe(struct i2c_client *client)
 	struct it6505 *it6505;
 	struct device *dev = &client->dev;
 	struct extcon_dev *extcon;
-	int err, intp_irq;
+	int err;
 
 	it6505 = devm_kzalloc(&client->dev, sizeof(*it6505), GFP_KERNEL);
 	if (!it6505)
@@ -3430,17 +3436,18 @@ static int it6505_i2c_probe(struct i2c_client *client)
 
 	it6505_parse_dt(it6505);
 
-	intp_irq = client->irq;
+	it6505->irq = client->irq;
 
-	if (!intp_irq) {
+	if (!it6505->irq) {
 		dev_err(dev, "Failed to get INTP IRQ");
 		err = -ENODEV;
 		return err;
 	}
 
-	err = devm_request_threaded_irq(&client->dev, intp_irq, NULL,
+	err = devm_request_threaded_irq(&client->dev, it6505->irq, NULL,
 					it6505_int_threaded_handler,
-					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT |
+					IRQF_NO_AUTOEN,
 					"it6505-intp", it6505);
 	if (err) {
 		dev_err(dev, "Failed to request INTP threaded IRQ: %d", err);
-- 
2.45.2.1089.g2a221341d9-goog