Input: focaltech - use explicitly signed char type

commit 8980f19094 upstream.

The recent change of -funsigned-char causes additions of negative
numbers to become additions of large positive numbers, leading to wrong
calculations of mouse movement. Change these casts to be explicitly
signed, to take into account negative offsets.

Fixes: 3bc753c06d ("kbuild: treat char as always unsigned")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217211
Link: https://lore.kernel.org/r/20230318133010.1285202-1-Jason@zx2c4.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason A. Donenfeld 2023-03-19 21:36:36 -07:00 committed by Greg Kroah-Hartman
parent 84ffc04166
commit cb22a9490b
1 changed files with 4 additions and 4 deletions

View File

@ -202,8 +202,8 @@ static void focaltech_process_rel_packet(struct psmouse *psmouse,
state->pressed = packet[0] >> 7;
finger1 = ((packet[0] >> 4) & 0x7) - 1;
if (finger1 < FOC_MAX_FINGERS) {
state->fingers[finger1].x += (char)packet[1];
state->fingers[finger1].y += (char)packet[2];
state->fingers[finger1].x += (s8)packet[1];
state->fingers[finger1].y += (s8)packet[2];
} else {
psmouse_err(psmouse, "First finger in rel packet invalid: %d\n",
finger1);
@ -218,8 +218,8 @@ static void focaltech_process_rel_packet(struct psmouse *psmouse,
*/
finger2 = ((packet[3] >> 4) & 0x7) - 1;
if (finger2 < FOC_MAX_FINGERS) {
state->fingers[finger2].x += (char)packet[4];
state->fingers[finger2].y += (char)packet[5];
state->fingers[finger2].x += (s8)packet[4];
state->fingers[finger2].y += (s8)packet[5];
}
}