[PATCH] input: mt: Initialize slots to unused

[Chase Douglas]

On Tue, 2010-08-24 at 10:28 +0200, Henrik Rydberg wrote:
> For MT slots, the ABS_MT_TRACKING_ID determines whether a slot is in use,
> but currently leaves initialization up to the drivers. This patch sets the
> slot state to unused upon creation.
> 
> Suggested for Maverick.
> 
> Signed-off-by: Henrik Rydberg <rydberg at euromail.se>
> ---
>  drivers/input/input.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index 085ea38..be58b63 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -1750,8 +1750,9 @@ EXPORT_SYMBOL(input_free_device);
>   * @dev: input device supporting MT events and finger tracking
>   * @num_slots: number of slots used by the device
>   *
> - * This function allocates all necessary memory for MT slot handling
> - * in the input device, and adds ABS_MT_SLOT to the device capabilities.
> + * This function allocates all necessary memory for MT slot handling in the
> + * input device, and adds ABS_MT_SLOT to the device capabilities. All slots
> + * are initially unused with ABS_MT_TRACKING_ID == -1.
>   */
>  int input_mt_create_slots(struct input_dev *dev, unsigned int num_slots)
>  {
> @@ -1764,6 +1765,8 @@ int input_mt_create_slots(struct input_dev *dev, unsigned int num_slots)
>  
>  	dev->mtsize = num_slots;
>  	input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
> +	while (num_slots--)
> +		dev->mt[num_slots].abs[ABS_MT_TRACKING_ID - ABS_MT_FIRST] = -1;
>  
>  	return 0;
>  }
> -- 
> 1.7.1

This just makes it easier for all the drivers who would have to do this
themselves. Looks good to me.

Acked-by: Chase Douglas <chase.douglas at canonical.com>