4ab8f7f320
5th and 6th byte of ALPS trackstick V3 protocol match condition for first byte of PS/2 3 bytes packet. When driver enters out of sync state and ALPS trackstick is sending data then driver match 5th, 6th and next 1st bytes as PS/2. It basically means if user is using trackstick when driver is in out of sync state driver will never resync. Processing these bytes as 3 bytes PS/2 data cause total mess (random cursor movements, random clicks) and make trackstick unusable until psmouse driver decide to do full device reset. Lot of users reported problems with ALPS devices on Dell Latitude E6440, E6540 and E7440 laptops. ALPS device or Dell EC for unknown reason send some invalid ALPS PS/2 bytes which cause driver out of sync. It looks like that i8042 and psmouse/alps driver always receive group of 6 bytes packets so there are no missing bytes and no bytes were inserted between valid ones. This patch does not fix root of problem with ALPS devices found in Dell Latitude laptops but it does not allow to process some (invalid) subsequence of 6 bytes ALPS packets as 3 bytes PS/2 when driver is out of sync. So with this patch trackstick input device does not report bogus data when also driver is out of sync, so trackstick should be usable on those machines. Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Tested-by: Pali Rohár <pali.rohar@gmail.com> Cc: stable@vger.kernel.org Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> |
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| .. | ||
| gameport | ||
| joystick | ||
| keyboard | ||
| misc | ||
| mouse | ||
| serio | ||
| tablet | ||
| touchscreen | ||
| apm-power.c | ||
| evbug.c | ||
| evdev.c | ||
| ff-core.c | ||
| ff-memless.c | ||
| input-compat.c | ||
| input-compat.h | ||
| input-mt.c | ||
| input-polldev.c | ||
| input.c | ||
| joydev.c | ||
| Kconfig | ||
| Makefile | ||
| matrix-keymap.c | ||
| mousedev.c | ||
| sparse-keymap.c | ||