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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Andi Shyti <andi.shyti@samsung.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.14 073/183] Input: stmfts - set IRQ_NOAUTOEN to the irq flag
Date:   Wed, 25 Apr 2018 12:34:53 +0200
Message-Id: <20180425103245.454700325@linuxfoundation.org>
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4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andi Shyti <andi.shyti@samsung.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@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/input/touchscreen/stmfts.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/input/touchscreen/stmfts.c
+++ b/drivers/input/touchscreen/stmfts.c
@@ -687,6 +687,14 @@ static int stmfts_probe(struct i2c_clien
 
 	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,
@@ -694,9 +702,6 @@ static int stmfts_probe(struct i2c_clien
 	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);