linux-kernel - [PATCH AUTOSEL for 4.15 072/189] Input: stmfts

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Message-ID: <20180409001637.162453-72-alexander.levin@microsoft.com>
Date:   Mon, 9 Apr 2018 00:17:41 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "stable@...r.kernel.org" <stable@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Andi Shyti <andi.shyti@...sung.com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 4.15 072/189] Input: stmfts - set IRQ_NOAUTOEN to
 the irq flag

From: Andi Shyti <andi.shyti@...sung.com>

[ Upstream commit cba04cdf437d745fac85220d1d692a9ae23d7004 ]

The interrupt is requested before the device is powered on and
it's value in some cases cannot be reliable. It happens on some
devices that an interrupt is generated as soon as requested
before having the chance to disable the irq.

Set the irq flag as IRQ_NOAUTOEN before requesting it.

This patch mutes the error:

  stmfts 2-0049: failed to read events: -11

received sometimes during boot time.

Signed-off-by: Andi Shyti <andi.shyti@...sung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
---
 drivers/input/touchscreen/stmfts.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
index 2a123e20a42e..efdb1a75a163 100644
--- a/drivers/input/touchscreen/stmfts.c
+++ b/drivers/input/touchscreen/stmfts.c
@@ -682,6 +682,14 @@ static int stmfts_probe(struct i2c_client *client,
 
 	input_set_drvdata(sdata->input, sdata);
 
+	/*
+	 * stmfts_power_on expects interrupt to be disabled, but
+	 * at this point the device is still off and I do not trust
+	 * the status of the irq line that can generate some spurious
+	 * interrupts. To be on the safe side it's better to not enable
+	 * the interrupts during their request.
+	 */
+	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
 	err = devm_request_threaded_irq(&client->dev, client->irq,
 					NULL, stmfts_irq_handler,
 					IRQF_ONESHOT,
@@ -689,9 +697,6 @@ static int stmfts_probe(struct i2c_client *client,
 	if (err)
 		return err;
 
-	/* stmfts_power_on expects interrupt to be disabled */
-	disable_irq(client->irq);
-
 	dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");
 
 	err = stmfts_power_on(sdata);
-- 
2.15.1