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From:   Takashi Iwai <tiwai@suse.de>
To:     Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] Input: elants_i2c - Fix NULL dereference at probing
Date:   Thu, 27 May 2021 19:31:53 +0200
Message-Id: <20210527173153.16470-1-tiwai@suse.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The recent change in elants_i2c driver to support more chips
introduced a regression leading to Oops at probing.  The driver reads
id->driver_data, but the id may be NULL depending on the device type
the driver gets bound.

Replace the driver data extraction with the device_get_match_data()
helper, and define the driver data in OF table, too.

Fixes: 9517b95bdc46 ("Input: elants_i2c - add support for eKTF3624")
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1186454
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
v1->v2: Use device_get_match_data()

 drivers/input/touchscreen/elants_i2c.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 17540bdb1eaf..29b5bb03cff9 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -1396,7 +1396,7 @@ static int elants_i2c_probe(struct i2c_client *client,
 	init_completion(&ts->cmd_done);
 
 	ts->client = client;
-	ts->chip_id = (enum elants_chip_id)id->driver_data;
+	ts->chip_id = (enum elants_chip_id)device_get_match_data(&client->dev);
 	i2c_set_clientdata(client, ts);
 
 	ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
@@ -1636,8 +1636,8 @@ MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
 
 #ifdef CONFIG_OF
 static const struct of_device_id elants_of_match[] = {
-	{ .compatible = "elan,ekth3500" },
-	{ .compatible = "elan,ektf3624" },
+	{ .compatible = "elan,ekth3500", .data = EKTH3500 },
+	{ .compatible = "elan,ektf3624", .data = EKTF3624 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, elants_of_match);
-- 
2.26.2