From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 05985534468 for ; Tue, 8 Sep 2026 12:20:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788870041; cv=none; b=deVzmt3nIiSI4LmIapMjoucsHDa1d14euSoaSLOToHEriBG1B3obRoUgzJ1Ih7O0Xacb29DV6R/dxycIiXlpAcDPQEv2H5LZK9dMLYgm5meOoIC1/vfW8E2Kb82nxytaqfMtJgstEoGMme4pO8mDDY21Tu+KSSLk7PyzuDRLSkA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788870041; c=relaxed/simple; bh=xy1c/KfIwQVbKY9gTmZbz/CtBR53yCxVkN4Z6OlIGnU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=n6kl3BzNQg4phPN8licl5HRUuTmiozsD+hwvu35juWWPH6JtEPRBO65l5acykFtcj14C9S2V1q4tUg5Jt4EXG1IxkpU2ffSPEex+VMq3Uwt09CnsGHuHa+7oypHTZEeIxfv4qOneuMI4wQjLMVU3XyM9MjR8HvocEUdThRro0p0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB9C81F00AC4; Tue, 8 Sep 2026 12:20:36 +0000 (UTC) From: Sasha Levin To: stable@vger.kernel.org Cc: Hongyan Xu , Geert Uytterhoeven , Andy Shevchenko , Sasha Levin Subject: [PATCH 5.10.y 2/2] auxdisplay: charlcd: cancel backlight work on registration failure Date: Tue, 8 Sep 2026 08:20:34 -0400 Message-ID: <20260908122034.2053198-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908122034.2053198-1-sashal@kernel.org> References: <2026090350-stencil-mud-1d68@gregkh> <20260908122034.2053198-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Hongyan Xu [ Upstream commit e3e3bf40916c1e810df03958cfa7ba6883cdce79 ] 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 Signed-off-by: Andy Shevchenko Signed-off-by: Sasha Levin --- 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 e74e25ff030b2..b3ff514f91a78 100644 --- a/drivers/auxdisplay/charlcd.c +++ b/drivers/auxdisplay/charlcd.c @@ -779,6 +779,16 @@ 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; @@ -843,8 +853,10 @@ 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); @@ -854,16 +866,11 @@ 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; } -- 2.53.0