On Wed, May 9, 2018 at 9:12 PM, Dmitry Torokhov <dtor@xxxxxxxxxx> wrote:
> From: Dmitry Torokhov <dtor@xxxxxxxxxxxx>
>
> On many Chromebooks touch devices are multi-sourced; the components are
> electrically compatible and one can be freely swapped for another without
> changing the OS image or firmware.
>
> To avoid bunch of scary messages when device is not actually present in the
> system let's try testing basic communication with it and if there is no
> response terminate probe early with -ENXIO.
>
> Signed-off-by: Dmitry Torokhov <dtor@xxxxxxxxxxxx>
> ---
Looks good. Tested on a Dell XPS with an i2c-hid touchpad:
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Cheers,
Benjamin
> drivers/hid/i2c-hid/i2c-hid.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index 7230243b94d30..a59d483ff316a 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -1048,6 +1048,14 @@ static int i2c_hid_probe(struct i2c_client *client,
> pm_runtime_enable(&client->dev);
> device_enable_async_suspend(&client->dev);
>
> + /* Make sure there is something at this address */
> + ret = i2c_smbus_read_byte(client);
> + if (ret < 0) {
> + dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
> + ret = -ENXIO;
> + goto err_pm;
> + }
> +
> ret = i2c_hid_fetch_hid_descriptor(ihid);
> if (ret < 0)
> goto err_pm;
> --
> 2.17.0.441.gb46fe60e1d-goog
>
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
