Re: [v2] Input: elan_i2c - check if device is there before really probing
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From: Guenter Roeck <linux@roeck-us.net>
Date: 2017-05-11 20:51:37
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On Mon, May 08, 2017 at 05:45:53PM -0700, Dmitry Torokhov wrote:
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 <dmitry.torokhov@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
quoted hunk ↗ jump to hunk
--- v2: switched over to i2c_smbus_read_byte() as Guenter suggested drivers/input/mouse/elan_i2c_core.c | 7 +++++++ 1 file changed, 7 insertions(+)diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c index 5d3b53dd2fa2..3b616cb7c67f 100644 --- a/drivers/input/mouse/elan_i2c_core.c +++ b/drivers/input/mouse/elan_i2c_core.c@@ -1091,6 +1091,13 @@ static int elan_probe(struct i2c_client *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)