[PATCH 0/3] [Maverick] UBUNTU: (evdev) Dynamic buffers (rev4)

[Chase Douglas]

On Thu, 2010-06-10 at 11:52 +0200, Henrik Rydberg wrote:
> These patches fixes a long-standing problem with occasionally dropped
> events from devices that produce a lot of them, such as MT
> devices. The problem is especially important to MT devices with
> contact tracking. The locking mechanism involved is not entirely
> trivial, and the ideal solution has been postponed upstream, until all
> details have been settled (multi-reader buffers, see
> http://lkml.org/lkml/2010/6/4/53). The enclosed patches
> (http://lkml.org/lkml/2010/6/5/59) are the ones being queued for
> 2.6.36.
> 
> Best regards,
> Henrik Rydberg
> 
> Henrik Rydberg (3):
>   UBUNTU: (evdev) Use multi-reader buffer to save space (rev4)
>   UBUNTU: (evdev) Convert to dynamic event buffer (rev4)
>   UBUNTU: (evdev) Use driver hint to compute the evdev buffer size
>     (rev2)
> 
>  drivers/input/evdev.c |   68 +++++++++++++++++++++++++++++++++----------------
>  include/linux/input.h |   17 ++++++++++++
>  2 files changed, 63 insertions(+), 22 deletions(-)

Details are in the patches, but this is a bug fix that should be useful
for our multitouch use. The first patch makes the evdev buffers better,
while the second and third are useful specifically for MT devices that
send lots of data. We will likely see patches coming to hint the evdev
buffer size in each driver.

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