Patch "Input: elan_i2c - check if device is there before really probing" has been added to the 4.4-stable tree

Patch "Input: elan_i2c - check if device is there before really probing" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    Input: elan_i2c - check if device is there before really probing

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     input-elan_i2c-check-if-device-is-there-before-really-probing.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Apr 10 10:31:53 CEST 2018
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Fri, 19 Dec 2014 12:57:49 -0800
Subject: Input: elan_i2c - check if device is there before really probing

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>


[ Upstream commit c5928551fd41b2eecdad78fa2be2a4a13ed5fde9 ]

Before trying to properly initialize the touchpad and generate bunch of
errors, let's first see it there is anything at the given address. If we
get error, fail silently with -ENXIO.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
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/mouse/elan_i2c_core.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -1082,6 +1082,13 @@ static int elan_probe(struct i2c_client
 		return error;
 	}
 
+	/* Make sure there is something at this address */
+	error = i2c_smbus_read_byte(client);
+	if (error < 0) {
+		dev_dbg(&client->dev, "nothing at this address: %d\n", error);
+		return -ENXIO;
+	}
+
 	/* Initialize the touchpad. */
 	error = elan_initialize(data);
 	if (error)


Patches currently in stable-queue which might be from dmitry.torokhov@gmail.com are

queue-4.4/input-elantech-force-relative-mode-on-a-certain-module.patch
queue-4.4/input-elan_i2c-check-if-device-is-there-before-really-probing.patch
queue-4.4/input-elan_i2c-clear-int-before-resetting-controller.patch