Re: [PATCH 4/6] hid: egalax: Report zero as minimum pressure

[Chase Douglas <chase.douglas@canonical.com>]

On Wed, 2010-10-13 at 15:58 +0200, Henrik Rydberg wrote:
> The firmware reports a logical minimum of one, but in order for
> userspace applications to correctly map all reported values to
> non-zero pressure, the driver needs to report a logical minimum of
> zero.  Fixed with this patch.
> 
> Tested-by: Philipp Merkel <mail@philmerk.de>
> Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
> ---
>  drivers/hid/hid-egalax.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/hid/hid-egalax.c b/drivers/hid/hid-egalax.c
> index 3b490a3..2aba897 100644
> --- a/drivers/hid/hid-egalax.c
> +++ b/drivers/hid/hid-egalax.c
> @@ -93,6 +93,7 @@ static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>  			input_set_events_per_packet(input, MAX_EVENTS);
>  			return 1;
>  		case HID_DG_TIPPRESSURE:
> +			field->logical_minimum = 0;
>  			hid_map_usage(hi, usage, bit, max,
>  					EV_ABS, ABS_MT_PRESSURE);
>  			set_abs(input, ABS_MT_PRESSURE, field, 0);

I'm a little unsure of whether the logical_minimum field should be
modified by the driver or if the range of the evdev property should be
the only change. I can't see anything in the hid code that looks like it
would be adversely affected by this change though.

-- Chase