On Mon, Jan 28, 2013 at 4:10 PM, Henrik Rydberg [off-list ref] wrote:

Hi Benjamin,

quoted

Relying on ALWAYS_VALID enhance a little the processing time of
the events.

Signed-off-by: Benjamin Tissoires <redacted>
---
 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.

No, the measure I made for this are roughly the same. It's purely
micro-optimization, and yes, mallocs must kill the processing time.
However, the purpose of this patch and the others entitled 'optimize
XXX' is to show that I did not invented the new default class. My true
objective is to remove all the quirks related to the 'valid'
information in order to have a driver as universal as possible and to
be able to clean it up.

Considering the must-be-tested-for-regression risk on top of that,
this patch falls far below what is worth doing, IMHO.

It _has_ been tested. I got the HID traces from FlatFrog and either
they use different firmwares with different processing in their
devices, the kernel processing is good.

Cheers,
Benjamin

quoted

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