From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4988BC433FE for ; Tue, 16 Nov 2021 19:18:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35C4E63220 for ; Tue, 16 Nov 2021 19:18:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239874AbhKPTU6 (ORCPT ); Tue, 16 Nov 2021 14:20:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:53800 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239873AbhKPTU5 (ORCPT ); Tue, 16 Nov 2021 14:20:57 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D661E63223; Tue, 16 Nov 2021 19:17:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637090279; bh=EjfK6ywtkTbYiXTxOr4yEkJELrvwgwMVwqnEQgNPO2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=frWfIpfU8B8hdkehcTUBtDi0OnSNOB/Kx9yM4kvNjk0KQY6XP2Q4N/+wyYk453KVB qKPWbovxQmJnL5hkSZ78JlgSCKz8hkfog2Y3udhiAz6b1orNHa5g0GeBwrWj8MU+f/ gObcCeD9SXptakUNFJFu1FwXYyNCs6us0dDhqXaelLJhY0EgxC4mGKHH6SLytM+oTA +p7TSvdz14QHPT25mEfOSCoZkWkBp8exNTz2nuJ9Il5cHJdJYtTFNmJJ4qxrB75NZa dPpWzEMfNBn8LTQ6753Sg2CxnpOv82xgEq8+Mg0cf/ZAJGCEfq6Avw18ut9jJhJgOZ UxkF/T+6gpiCg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Daniel Thompson , Lee Jones , Sasha Levin , jingoohan1@gmail.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 03/65] backlight: Propagate errors from get_brightness() Date: Tue, 16 Nov 2021 14:16:48 -0500 Message-Id: <20211116191754.2419097-3-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211116191754.2419097-1-sashal@kernel.org> References: <20211116191754.2419097-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org From: Thomas Weißschuh [ Upstream commit 563edf85ce18a90dd0a7b39e279a691d937205f6 ] backlight.h documents "struct backlight_ops->get_brightness()" to return a negative errno on failure. So far these errors have not been handled in the backlight core. This leads to negative values being exposed through sysfs although only positive values are documented to be reported. Signed-off-by: Thomas Weißschuh Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones Signed-off-by: Sasha Levin --- drivers/video/backlight/backlight.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 537fe1b376ad7..4658cfb75aa28 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -292,10 +292,13 @@ static ssize_t actual_brightness_show(struct device *dev, struct backlight_device *bd = to_backlight_device(dev); mutex_lock(&bd->ops_lock); - if (bd->ops && bd->ops->get_brightness) - rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd)); - else + if (bd->ops && bd->ops->get_brightness) { + rc = bd->ops->get_brightness(bd); + if (rc >= 0) + rc = sprintf(buf, "%d\n", rc); + } else { rc = sprintf(buf, "%d\n", bd->props.brightness); + } mutex_unlock(&bd->ops_lock); return rc; @@ -381,9 +384,18 @@ ATTRIBUTE_GROUPS(bl_device); void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason) { + int brightness; + mutex_lock(&bd->ops_lock); - if (bd->ops && bd->ops->get_brightness) - bd->props.brightness = bd->ops->get_brightness(bd); + if (bd->ops && bd->ops->get_brightness) { + brightness = bd->ops->get_brightness(bd); + if (brightness >= 0) + bd->props.brightness = brightness; + else + dev_err(&bd->dev, + "Could not update brightness from device: %pe\n", + ERR_PTR(brightness)); + } mutex_unlock(&bd->ops_lock); backlight_generate_event(bd, reason); } -- 2.33.0