Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 737B0C74A5B for ; Sat, 18 Mar 2023 13:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229677AbjCRNa0 (ORCPT ); Sat, 18 Mar 2023 09:30:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229502AbjCRNaY (ORCPT ); Sat, 18 Mar 2023 09:30:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D816D303FE; Sat, 18 Mar 2023 06:30:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0A6D760C69; Sat, 18 Mar 2023 13:30:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FD4FC433D2; Sat, 18 Mar 2023 13:30:20 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="WKCKR3gP" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1679146217; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Nqr/nUnieHd8r4zheNL21KlePfDeA8yZBuwwN9r8k3A=; b=WKCKR3gP1Tnb355ZsuLfODImva+5vZoE0VRH5sszMUhW7DjWsC/OybL9flZ/lNbuW6gQql DmKVIZhdh0+7BU3uNdllcMFYumCKzKC1phn+GS/dnbzDQkqhLCIxNWCO7VRakLHilNFiur EPGaVd7JdsozAfyFHeiXcDVj/TBOiK4= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 33af9d47 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Sat, 18 Mar 2023 13:30:17 +0000 (UTC) From: "Jason A. Donenfeld" To: dmitry.torokhov@gmail.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, regressions@lists.linux.dev Cc: "Jason A. Donenfeld" , stable@vger.kernel.org, regressions@leemhuis.info, barry@messagefor.me.uk Subject: [PATCH] Input: focaltech - use explicitly signed char type Date: Sat, 18 Mar 2023 14:30:10 +0100 Message-Id: <20230318133010.1285202-1-Jason@zx2c4.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 explictly signed, to take into account negative offsets. Fixes: 3bc753c06dd0 ("kbuild: treat char as always unsigned") Cc: stable@vger.kernel.org Cc: regressions@leemhuis.info Cc: barry@messagefor.me.uk Signed-off-by: Jason A. Donenfeld --- Wrote this patch from my phone, untested, so it would be nice if somebody with hardware could confirm it works. drivers/input/mouse/focaltech.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/input/mouse/focaltech.c b/drivers/input/mouse/focaltech.c index 6fd5fff0cbff..3dbad0d8e8c9 100644 --- a/drivers/input/mouse/focaltech.c +++ b/drivers/input/mouse/focaltech.c @@ -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 += (signed char)packet[1]; + state->fingers[finger1].y += (signed char)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 += (signed char)packet[4]; + state->fingers[finger2].y += (signed char)packet[5]; } } -- 2.40.0