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authorDmitry Torokhov <dtor@insightbb.com>2007-04-12 01:31:55 -0400
committerDmitry Torokhov <dtor@insightbb.com>2007-04-12 01:31:55 -0400
commit0d9d93c411c9351ba186f5ec910b10da7c1d9d14 (patch)
tree4c4752f0d4774d1cc3353facad0daba4c0de7285
parentInput: ALPS - handle errors from input_register_device() (diff)
downloadlinux-dev-0d9d93c411c9351ba186f5ec910b10da7c1d9d14.tar.xz
linux-dev-0d9d93c411c9351ba186f5ec910b10da7c1d9d14.zip
Input: mousedev - fix sudden warps with touchpads
Pete Zaitcev reports that with his touchpad, if he lifts the finger and places it elsewhere, the pointer sometimes warps dramatically. This happens because we don't store coordinates unless we detect a touch so sometimes we have stale coordinates in queue (from where the finger left the pad) and averaging makes cursor to jump across the screen. The solution is to always store the latest coordinates. Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
-rw-r--r--drivers/input/mousedev.c51
1 files changed, 26 insertions, 25 deletions
diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index 764970f5da2e..3b8011c56c86 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c
@@ -124,32 +124,33 @@ static void mousedev_touchpad_event(struct input_dev *dev, struct mousedev *mous
int size, tmp;
enum { FRACTION_DENOM = 128 };
- if (mousedev->touch) {
- size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
- if (size == 0)
- size = 256 * 2;
-
- switch (code) {
- case ABS_X:
- fx(0) = value;
- if (mousedev->pkt_count >= 2) {
- tmp = ((value - fx(2)) * (256 * FRACTION_DENOM)) / size;
- tmp += mousedev->frac_dx;
- mousedev->packet.dx = tmp / FRACTION_DENOM;
- mousedev->frac_dx = tmp - mousedev->packet.dx * FRACTION_DENOM;
- }
- break;
+ switch (code) {
+ case ABS_X:
+ fx(0) = value;
+ if (mousedev->touch && mousedev->pkt_count >= 2) {
+ size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
+ if (size == 0)
+ size = 256 * 2;
+ tmp = ((value - fx(2)) * (256 * FRACTION_DENOM)) / size;
+ tmp += mousedev->frac_dx;
+ mousedev->packet.dx = tmp / FRACTION_DENOM;
+ mousedev->frac_dx = tmp - mousedev->packet.dx * FRACTION_DENOM;
+ }
+ break;
- case ABS_Y:
- fy(0) = value;
- if (mousedev->pkt_count >= 2) {
- tmp = -((value - fy(2)) * (256 * FRACTION_DENOM)) / size;
- tmp += mousedev->frac_dy;
- mousedev->packet.dy = tmp / FRACTION_DENOM;
- mousedev->frac_dy = tmp - mousedev->packet.dy * FRACTION_DENOM;
- }
- break;
- }
+ case ABS_Y:
+ fy(0) = value;
+ if (mousedev->touch && mousedev->pkt_count >= 2) {
+ /* use X size to keep the same scale */
+ size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
+ if (size == 0)
+ size = 256 * 2;
+ tmp = -((value - fy(2)) * (256 * FRACTION_DENOM)) / size;
+ tmp += mousedev->frac_dy;
+ mousedev->packet.dy = tmp / FRACTION_DENOM;
+ mousedev->frac_dy = tmp - mousedev->packet.dy * FRACTION_DENOM;
+ }
+ break;
}
}