From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932291AbdEDGaB (ORCPT ); Thu, 4 May 2017 02:30:01 -0400 Received: from mail-pg0-f68.google.com ([74.125.83.68]:34723 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932087AbdEDG3v (ORCPT ); Thu, 4 May 2017 02:29:51 -0400 Date: Wed, 3 May 2017 23:29:38 -0700 From: Dmitry Torokhov To: linux-input@vger.kernel.org Cc: KT Liao , Guenter Roeck , linux-kernel@vger.kernel.org Subject: [PATCH] Input: elan_i2c - check if device is there before really probing Message-ID: <20170504062938.GA30771@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/elan_i2c_core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c index 5d3b53dd2fa2..0479730e7c5c 100644 --- a/drivers/input/mouse/elan_i2c_core.c +++ b/drivers/input/mouse/elan_i2c_core.c @@ -1040,6 +1040,7 @@ static int elan_probe(struct i2c_client *client, const struct elan_transport_ops *transport_ops; struct device *dev = &client->dev; struct elan_tp_data *data; + union i2c_smbus_data dummy; unsigned long irqflags; int error; @@ -1091,6 +1092,14 @@ static int elan_probe(struct i2c_client *client, return error; } + /* Make sure there is something at this address */ + error = i2c_smbus_xfer(client->adapter, client->addr, 0, + I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); + if (error) { + dev_dbg(&client->dev, "nothing at this address: %d\n", error); + return -ENXIO; + } + /* Initialize the touchpad. */ error = elan_initialize(data); if (error) -- 2.13.0.rc1.294.g07d810a77f-goog -- Dmitry