Re: [PATCH v5 2/9] Input: goodix - use actual config length for each device type

[Bastien Nocera <hadess@hadess.net>]

On Mon, 2015-09-07 at 17:36 +0300, Irina Tirdea wrote:
> Each of the Goodix devices supported by this driver has a fixed size
> for
> the configuration information registers. The size varies depending on
> the
> device and is specified in the datasheet.
> 
> Use the proper configuration length as specified in the datasheet for
> each device model, so we do not read more than the actual size of the
> configuration registers.
> 
> Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>

Acked-by: Bastien Nocera <hadess@hadess.net>

> ---
>  drivers/input/touchscreen/goodix.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c
> b/drivers/input/touchscreen/goodix.c
> index 6ae28c5..7be6eab 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -36,6 +36,7 @@ struct goodix_ts_data {
>  	unsigned int max_touch_num;
>  	unsigned int int_trigger_type;
>  	bool rotated_screen;
> +	int cfg_len;
>  };
>  
>  #define GOODIX_MAX_HEIGHT		4096
> @@ -45,6 +46,8 @@ struct goodix_ts_data {
>  #define GOODIX_MAX_CONTACTS		10
>  
>  #define GOODIX_CONFIG_MAX_LENGTH	240
> +#define GOODIX_CONFIG_911_LENGTH	186
> +#define GOODIX_CONFIG_967_LENGTH	228
>  
>  /* Register defines */
>  #define GOODIX_READ_COOR_ADDR		0x814E
> @@ -115,6 +118,23 @@ static int goodix_i2c_read(struct i2c_client
> *client,
>  	return ret < 0 ? ret : (ret != ARRAY_SIZE(msgs) ? -EIO : 0);
>  }
>  
> +static int goodix_get_cfg_len(u16 id)
> +{
> +	switch (id) {
> +	case 911:
> +	case 9271:
> +	case 9110:
> +	case 927:
> +	case 928:
> +		return GOODIX_CONFIG_911_LENGTH;
> +	case 912:
> +	case 967:
> +		return GOODIX_CONFIG_967_LENGTH;
> +	default:
> +		return GOODIX_CONFIG_MAX_LENGTH;
> +	}
> +}
> +
>  static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8
> *data)
>  {
>  	int touch_num;
> @@ -230,8 +250,7 @@ static void goodix_read_config(struct
> goodix_ts_data *ts)
>  	int error;
>  
>  	error = goodix_i2c_read(ts->client, GOODIX_REG_CONFIG_DATA,
> -				config,
> -				GOODIX_CONFIG_MAX_LENGTH);
> +				config, ts->cfg_len);
>  	if (error) {
>  		dev_warn(&ts->client->dev,
>  			 "Error reading config (%d), using
> defaults\n",
> @@ -398,6 +417,8 @@ static int goodix_ts_probe(struct i2c_client
> *client,
>  		return error;
>  	}
>  
> +	ts->cfg_len = goodix_get_cfg_len(id_info);
> +
>  	goodix_read_config(ts);
>  
>  	error = goodix_request_input_dev(ts, version_info, id_info);