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| author | Vadim Zaliva <lord@crocodile.org> | 2010-03-10 23:41:00 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2010-03-11 00:00:56 -0800 |
| commit | 04b4b88cca0ebe3813b4b6f014fb6a0db380b137 (patch) | |
| tree | e433748561def86a9568b3adb988b5a187e79ee5 | |
| parent | 4eb6f91b95e7618eae0103b6cba7c7f01f9d40f3 (diff) | |
| download | linux-04b4b88cca0ebe3813b4b6f014fb6a0db380b137.tar.gz linux-04b4b88cca0ebe3813b4b6f014fb6a0db380b137.tar.bz2 linux-04b4b88cca0ebe3813b4b6f014fb6a0db380b137.zip | |
Input: appletouch - fix integer overflow issue
When reading data from Geyser 2 touchpads used on post Oct 2005 Apple
PowerBooks the driver was casting X and Y coordinates values to
'signed char'. Testing on one of such PowerBooks I have noticed that
touchpad always generates positive values, but some of them are greater
that 127, and thus, when cast to 'signed char' being interpreted as
a negative.
Such bigger values have been observed infrequently, closer to the
edges of a touchpad, so the problem was not very visible.
Nevertheless, the patch would potentially improve touchpad
driver accuracy.
Signed-off-by: Vadim Zaliva <lord@crocodile.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
| -rw-r--r-- | drivers/input/mouse/appletouch.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/input/mouse/appletouch.c b/drivers/input/mouse/appletouch.c index 908b5b44052f..53ec7ddd1826 100644 --- a/drivers/input/mouse/appletouch.c +++ b/drivers/input/mouse/appletouch.c @@ -205,8 +205,8 @@ struct atp { bool overflow_warned; int x_old; /* last reported x/y, */ int y_old; /* used for smoothing */ - signed char xy_cur[ATP_XSENSORS + ATP_YSENSORS]; - signed char xy_old[ATP_XSENSORS + ATP_YSENSORS]; + u8 xy_cur[ATP_XSENSORS + ATP_YSENSORS]; + u8 xy_old[ATP_XSENSORS + ATP_YSENSORS]; int xy_acc[ATP_XSENSORS + ATP_YSENSORS]; int idlecount; /* number of empty packets */ struct work_struct work; @@ -531,7 +531,7 @@ static void atp_complete_geyser_1_2(struct urb *urb) for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) { /* accumulate the change */ - signed char change = dev->xy_old[i] - dev->xy_cur[i]; + int change = dev->xy_old[i] - dev->xy_cur[i]; dev->xy_acc[i] -= change; /* prevent down drifting */ |