Re: [PATCH 06/25] HID: multitouch: optimize FlatFrog panels

From: Henrik Rydberg
Date: Mon Jan 28 2013 - 10:04:47 EST


Hi Benjamin,

> Relying on ALWAYS_VALID enhance a little the processing time of
> the events.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx>
> ---
> drivers/hid/hid-multitouch.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)

Is there a measurement backing up this claim? I suspect
micro-optimizations of this kind drowns completely along the rather
long way from device, via malloc and loops, to the input core.
Considering the must-be-tested-for-regression risk on top of that,
this patch falls far below what is worth doing, IMHO.

> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index 5a886bd..7dfe891 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -229,8 +229,9 @@ static struct mt_class mt_classes[] = {
> },
>
> { .name = MT_CLS_FLATFROG,
> - .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
> - MT_QUIRK_NO_AREA,
> + .quirks = MT_QUIRK_ALWAYS_VALID |
> + MT_QUIRK_NO_AREA |
> + MT_QUIRK_CONTACT_CNT_ACCURATE,
> .sn_move = 2048,
> .maxcontacts = 40,
> },
> --
> 1.8.1
>

Thanks.
Henrik
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