[PATCH 1/5] m68k: Fix atari mouse movement

From: Miro Kropacek <[email protected]>

Kernels are built with -funsigned-char since version 6.2, resulting
in signed mouse position deltas getting misinterpreted as unsigned.

Cast deltas passed in (unsigned) scancode buffer to correctly
interpret sign.

Fixes: 3bc753c06dd02a35 ("kbuild: treat char as always unsigned")
Link: https://lists.debian.org/debian-68k/2026/08/msg00000.html
Signed-off-by: Miro Kropacek <[email protected]>
Reviewed-by: Michael Schmitz <[email protected]>
---
 drivers/input/mouse/atarimouse.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/input/mouse/atarimouse.c b/drivers/input/mouse/atarimouse.c
index b1219cc4d9a2..351aab69e905 100644
--- a/drivers/input/mouse/atarimouse.c
+++ b/drivers/input/mouse/atarimouse.c
@@ -70,9 +70,12 @@ static void atamouse_interrupt(char *buf)
 	atari_mouse_buttons = buttons;
 #endif
 
-	/* only relative events get here */
-	dx = buf[1];
-	dy = buf[2];
+	/* only relative events get here; the IKBD sends signed 8-bit
+	 * deltas, and the kernel builds with -funsigned-char since 6.2,
+	 * so an explicit signed cast is required
+	 */
+	dx = (s8)buf[1];
+	dy = (s8)buf[2];
 
 	input_report_rel(atamouse_dev, REL_X, dx);
 	input_report_rel(atamouse_dev, REL_Y, dy);
-- 
2.17.1