From nobody Thu Apr 9 06:38:40 2026 Received: from xmbghk7.mail.qq.com (xmbghk7.mail.qq.com [43.163.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1BF91371067 for ; Tue, 10 Mar 2026 11:16:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=43.163.128.53 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773141412; cv=none; b=YRXd1pb21/I7Pf91Vv/MyosgInlJeesodoDGKBfiXU/fBwtM6vMtkZZKdvk34Si9U9NYFOnolLHA6QvXp7udmScvti4ezY8fkYiwFXgEg2WnjTI2gq9OtFqPXdhZNrw5KWplsEiy10HadqeXELOn1z7N7R02f9/4wzRa2A5YaA4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773141412; c=relaxed/simple; bh=d5UnIigyg6bakYpdaE+fo6280nQNVHEVnUXYcUbfV+8=; h=Message-ID:From:To:Cc:Subject:Date:MIME-Version; b=npZiA868cD7/DyUv8SD8XsbDsKZSCIcBY88CzfFd1bGrCmhpyqAH5VAzIegTfYQVwoJ8RgS8TQmEE7Vj7jD4lw6Ke6qR7yM941qiGomSiNWznTPTHh65ONbExv6t6tuJwfzz9j2QUAZqKUVwBsmxzGQj+3QLWt8iur7TkFhD64A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=Yvd3oDrw; arc=none smtp.client-ip=43.163.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="Yvd3oDrw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1773141406; bh=6WpV5CoBRYFQ+ALA39HsvcjBe4MfWP1mhkJGTfvk/MA=; h=From:To:Cc:Subject:Date; b=Yvd3oDrwQaGbmUem43j7rB/KqJLsDCaPDe4OvWPO0PiuNZDmlPGBi8Vo3aFg3TDQx WYQMnLKV5O7oVNpx4qMqi4+XYV57N0cGZpgsyL4gp4CjdzlT0/nZikWxTgbDfxqXlj 2GVEUUlptGpkUgLcS0DzkN+MvFOXF+6lJTpmy2gA= Received: from June.localdomain ([123.121.145.35]) by newxmesmtplogicsvrsza63-0.qq.com (NewEsmtp) with SMTP id 34C2989B; Tue, 10 Mar 2026 19:13:12 +0800 X-QQ-mid: xmsmtpt1773141192tcplc4j6f Message-ID: X-QQ-XMAILINFO: Nx5J06Esz7r74PTjywLiWaje8P18VwKDZundTnr5Pl11KATI6qiOkc339bcBgi e3y8niXidby+OdBmrj0D5tMDCF3vp7hOrfSbwGQdD5QzS/W+AlDaXQWJrcnjdlhKUIDToagUGrqx my5vMZyJI2hna2OgO9LFmOOCPEtTfLvxz/J9FWQ9ye5uuTwLmxPwIRR50kEg+FzCOgDvp33glAf4 NegU1zd5iwOKl20/F3icwzEk+NJQuv/NvVjcepVdt84hhKhzFg4Ioyq1RVAufh7mfVWvQ4nxL//o Rx5ykkqABSPp2WeFeev3CFcxlGQoHkMlczdDYWlrM7vW3PnhyG8fAhIAy9TF6KpwtcGGOqJSvuY2 9M89tRQ6rr8kLqyWZf8FnV/vSQqFwKby/beYnWvdKEhneeLg1o5gKHy/XLobEgqtclKQH6KpJvEF Tm9lEUxiyJaYL04w1a6TfH3D+/xfQq6Za0KUYKWMFtLTtzxARti5uP1FFaWKSIU6Zk7EkcNgVEAl MVDOenshyst0ex78wme2sBvbSZG8oc/0xp+orAyfnA0mzjof/VhDQGmN1ufGxOfye/rvoIAj5/mO t/QMd3qJZOwYHMLc2Op5oAquYkafbTN8aPo3Wszy5161OMcvcBjzaTcvh5rcBsz501LVz+/MDNt8 k6Bl/JIS2ZD8/Zgf7mz3bWoBObSe5a4uBOyRT2sr3CsCC2iL5n+A77RBoqeRB4KN4qab+uSQigt+ zc74feSOzEwcIAgaV/lR4dHjQwbtsX5KDvtgJRq3MduYWMo0G1KLb05zY3s6cq5hPJThYn03DRDA 7DWubUNUCfZnt2JBYgJW/+azYdYUnrXid/sr8s61khLHzUxuSMtJOLZWTor4u49HL4Pk7hVGd61o wK9uukX3xEmIL1osP+7AjqjE661FcQDSfG4bfW38GCcCgzqT1R0a8xCEnM9MZnOAtZOWHIRx/juS tw8C6SwjFkC5esHjc1M95eZX5hGefH44WWuW/Sth8pjEjxzU/HpCeXxOXAJNOp8FtOs6XTEUphRJ WzgUFdbJ6FqgV6AhV3E81uFq1G9ycvNvhmEaPWjKSKJ7xBvr9O7nRlZjUlawqSj/ulvE6d/ivCP5 CmKF+sfyd5qL/ScuIn7tr2Iye64YUYcs+vKhQTa+qNhduKE1FJDLlSngea+WS9c1P5yN08 X-QQ-XMRINFO: NI4Ajvh11aEjEMj13RCX7UuhPEoou2bs1g== From: king <1742789905@qq.com> To: Andy Shevchenko , Geert Uytterhoeven Cc: linux-kernel@vger.kernel.org, Andrew Morton , Randy Dunlap , gszhai@bjtu.edu.cn, 25125332@bjtu.edu.cn, 25125283@bjtu.edu.cn, 23120469@bjtu.edu.cn, Wang Jun <1742789905@qq.com> Subject: [PATCH] auxdisplay: lcd2s: add error handling for i2c transfers Date: Tue, 10 Mar 2026 19:13:08 +0800 X-OQ-MSGID: <20260310111308.14654-1-1742789905@qq.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Wang Jun <1742789905@qq.com> The lcd2s_print() and lcd2s_gotoxy() functions currently ignore the return value of lcd2s_i2c_master_send(), which can fail. This can lead to silent data loss or incorrect cursor positioning. Add proper error checking: if the number of bytes sent does not match the expected length, return -EIO; otherwise propagate any error code from the I2C transfer. Signed-off-by: Wang Jun <1742789905@qq.com> --- drivers/auxdisplay/lcd2s.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/auxdisplay/lcd2s.c b/drivers/auxdisplay/lcd2s.c index defb0573e43c..9ae5f48cbd6c 100644 --- a/drivers/auxdisplay/lcd2s.c +++ b/drivers/auxdisplay/lcd2s.c @@ -99,8 +99,13 @@ static int lcd2s_print(struct charlcd *lcd, int c) { struct lcd2s_data *lcd2s =3D lcd->drvdata; u8 buf[2] =3D { LCD2S_CMD_WRITE, c }; + int ret; =20 - lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); + ret =3D lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); + if (ret < 0) + return ret; + if (ret !=3D sizeof(buf)) + return -EIO; return 0; } =20 @@ -108,9 +113,13 @@ static int lcd2s_gotoxy(struct charlcd *lcd, unsigned = int x, unsigned int y) { struct lcd2s_data *lcd2s =3D lcd->drvdata; u8 buf[3] =3D { LCD2S_CMD_CUR_POS, y + 1, x + 1 }; - - lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); - + int ret; + + ret =3D lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); + if (ret < 0) + return ret; + if (ret !=3D sizeof(buf)) + return -EIO; return 0; } =20 --=20 2.43.0