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 957A1C433FE for ; Tue, 16 Nov 2021 19:04:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70F6D63223 for ; Tue, 16 Nov 2021 19:04:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239775AbhKPTHr (ORCPT ); Tue, 16 Nov 2021 14:07:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:51282 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239755AbhKPTHr (ORCPT ); Tue, 16 Nov 2021 14:07:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id BE2476321B; Tue, 16 Nov 2021 19:04:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637089489; bh=EjfK6ywtkTbYiXTxOr4yEkJELrvwgwMVwqnEQgNPO2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PqEHdSkt9INv9sFbakw6AsNAz3ncErGskJRspBd/s9V1+OIt2FaZ/EVNzFERr5wPC QdwIji9HXkKT0trN5E6V1aJC/PpHW3L2E1oPFSViiVBeSONKngDd8zL3Gv6WGlvTpg hievjzjGACr286+JAFvA3E6bD77/v8EM4FPo8BjMjsBoeaQnZFaL4OvSWcyK65SdV6 JWEcR0fK2zzyW4VTWNwjYJj7CzpwkgJ7RzihgbtNZHoMxN2qO3xOCKcrKCNQpnWtsP J++C9u3LEXYdnUpz9uFLKKeSMmjNRcGELMPhJ7iLUYjTZ/tkCOZJor11NxUKhbI0FU HP00DWZ019Xsw== 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 14:03:23 -0500 Message-Id: <20211116190443.2418144-3-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211116190443.2418144-1-sashal@kernel.org> References: <20211116190443.2418144-1-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