From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-m49197.qiye.163.com (mail-m49197.qiye.163.com [45.254.49.197]) (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 D6C813E5597; Sat, 15 Aug 2026 11:00:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.254.49.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786791607; cv=none; b=Fk/JWmB4+MGOm26eqwJ/O3XIJkDulDdDeHfiXvndO1NglpG0bpLyKbjoMoz76BGGyuYyaGISyl9xHw9luN9rW+hiT62R0xMnEM5K1eMTWoXh5kvv+WTAlutHdJDllxLjHWyTqYmwfOJrj0BM/U2+l4HU7K54ZiIDuwr569gVLms= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786791607; c=relaxed/simple; bh=IxQYtUnxC7ypQ0W3xXA9a4Tw2ArFtk+Pme7EPeFhlfw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=WWuLyqS1nrsWF2ylBvw7KWpLxPKZFr2dB37l+zHBlz53HQiLDQWjGoq+oKBEkrTdgPWWQqhNd38sxCbvv0sDnkBzDTGsDr1VTmNyXlvHUXnqnLwDuHz2JNYNecsYmMoIu+MmZG+dfGaEtTxlloh5fZa06b8tIPyi0LQB1bJD/QI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=seu.edu.cn; spf=pass smtp.mailfrom=seu.edu.cn; dkim=pass (1024-bit key) header.d=seu.edu.cn header.i=@seu.edu.cn header.b=Bl83rdnU; arc=none smtp.client-ip=45.254.49.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=seu.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=seu.edu.cn Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=seu.edu.cn header.i=@seu.edu.cn header.b="Bl83rdnU" Received: from LAPTOP-99KJFSET (unknown [36.153.54.46]) by smtp.qiye.163.com (Hmail) with ESMTP id 4a18d00a4; Sat, 15 Aug 2026 18:59:52 +0800 (GMT+08:00) From: Hongyan Xu To: Andy Shevchenko Cc: Andy Shevchenko , Geert Uytterhoeven , Miguel Ojeda , Miguel Ojeda , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jianhao Xu , Lars Poeschel , Willy Tarreau , Hongyan Xu Subject: [PATCH v3] auxdisplay: charlcd: cancel backlight work on registration failure Date: Sat, 15 Aug 2026 18:59:50 +0800 Message-ID: <20260815105950.1109-1-getshell@seu.edu.cn> X-Mailer: git-send-email 2.50.1.windows.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-HM-Tid: 0aa00513ff8003a1kunm8a5f04f88811d X-HM-MType: 10 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkZTElMVk8YS01LTk9JTB4ZGFYeHw 5VEwETFhoSFyQUDg9ZV1kYEgtZQVlITVVKTkhVTk9VT01ZV1kWGg8SFR0UWUFZT0tIVUpLSEpPSE xVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=Bl83rdnUa6Qctt7FzHoO3wYAaWTbLb5wEbZwa5BVdOPbS6UqNRe+iGdp5i3kkvcy+Qr2xMYfiLAeHDKNkh/WS5JwBHVEjLGZV3ptW9CiQYiKw2BTTzuCspmV49P3xvHaXX33z/YF8YtkDZAn1AqsXqG4yYefDAJHIF/fYbdzNZo=; c=relaxed/relaxed; s=default; d=seu.edu.cn; v=1; bh=mPNWPXZxtyUvG3jAFyp2u/hbL/X9NiQFk87ViIjDq6o=; h=date:mime-version:subject:message-id:from; With CONFIG_CHARLCD_BL_FLASH, charlcd_init() schedules bl_work before charlcd_register() calls misc_register(). If registration fails, the caller frees the charlcd object while delayed work still contains its address. Add charlcd_deinit() to cancel the delayed work and turn the backlight off. Use it for both registration rollback and normal unregistration. Fixes: 39f8ea46724e ("auxdisplay: charlcd: Extract character LCD core from misc/panel") Cc: stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven Signed-off-by: Hongyan Xu --- Changes in v3: - Add Cc: stable@vger.kernel.org (Miguel). Changes in v2: - Factor the backlight cleanup into charlcd_deinit() and reuse it from charlcd_unregister() (Andy, Geert). - Add the Fixes tag (Andy). drivers/auxdisplay/charlcd.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c index 09020bb8ad15..ae2692ec3963 100644 --- a/drivers/auxdisplay/charlcd.c +++ b/drivers/auxdisplay/charlcd.c @@ -595,6 +595,16 @@ static int charlcd_init(struct charlcd *lcd) return 0; } +static void charlcd_deinit(struct charlcd *lcd) +{ + struct charlcd_priv *priv = charlcd_to_priv(lcd); + + if (lcd->ops->backlight) { + cancel_delayed_work_sync(&priv->bl_work); + lcd->ops->backlight(lcd, CHARLCD_OFF); + } +} + struct charlcd *charlcd_alloc(unsigned int drvdata_size) { struct charlcd_priv *priv; @@ -654,8 +664,10 @@ int charlcd_register(struct charlcd *lcd) return ret; ret = misc_register(&charlcd_dev); - if (ret) + if (ret) { + charlcd_deinit(lcd); return ret; + } the_charlcd = lcd; register_reboot_notifier(&panel_notifier); @@ -665,16 +677,11 @@ EXPORT_SYMBOL_GPL(charlcd_register); int charlcd_unregister(struct charlcd *lcd) { - struct charlcd_priv *priv = charlcd_to_priv(lcd); - unregister_reboot_notifier(&panel_notifier); charlcd_puts(lcd, "\x0cLCD driver unloaded.\x1b[Lc\x1b[Lb\x1b[L-"); misc_deregister(&charlcd_dev); the_charlcd = NULL; - if (lcd->ops->backlight) { - cancel_delayed_work_sync(&priv->bl_work); - priv->lcd.ops->backlight(&priv->lcd, CHARLCD_OFF); - } + charlcd_deinit(lcd); return 0; } -- 2.50.1.windows.1