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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE8C6CD13CF for ; Sun, 17 Sep 2023 20:32:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241010AbjIQUcC (ORCPT ); Sun, 17 Sep 2023 16:32:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241070AbjIQUbg (ORCPT ); Sun, 17 Sep 2023 16:31:36 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0534C10F for ; Sun, 17 Sep 2023 13:31:31 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C657C433CD; Sun, 17 Sep 2023 20:31:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694982690; bh=p0ZewTQoaaLjtbAlbhx/Izk4prT5Dxm9vyRoqQFEmCM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cb1ePaz9x5knOoUS00tcgoS6DVXzuPAAL+JEYWXipJFf0IqTagfCG+reDpUgcdP74 nVOHDMRaOaHCkYNkI/K8h1S/0n/AnzYEhQStGZPn0y/heMnyv0vQ6Kvi33MFA1WhN+ 7gPeBF6rIKPkdCkpkk9nCQ4y3ABx9hUwzSENNimw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Marek=20Beh=C3=BAn?= , Lee Jones , Sasha Levin Subject: [PATCH 5.15 307/511] leds: multicolor: Use rounded division when calculating color components Date: Sun, 17 Sep 2023 21:12:14 +0200 Message-ID: <20230917191121.241419653@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191113.831992765@linuxfoundation.org> References: <20230917191113.831992765@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marek Behún [ Upstream commit 065d099f1be58187e6629273c50b948a02b7e1bf ] Given channel intensity, LED brightness and max LED brightness, the multicolor LED framework helper led_mc_calc_color_components() computes the color channel brightness as chan_brightness = brightness * chan_intensity / max_brightness Consider the situation when (brightness, intensity, max_brightness) is for example (16, 15, 255), then chan_brightness is computed to 0 although the fractional divison would give 0.94, which should be rounded to 1. Use DIV_ROUND_CLOSEST here for the division to give more realistic component computation: chan_brightness = DIV_ROUND_CLOSEST(brightness * chan_intensity, max_brightness) Fixes: 55d5d3b46b08 ("leds: multicolor: Introduce a multicolor class definition") Signed-off-by: Marek Behún Link: https://lore.kernel.org/r/20230801124931.8661-1-kabel@kernel.org Signed-off-by: Lee Jones Signed-off-by: Sasha Levin --- drivers/leds/led-class-multicolor.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c index e317408583df9..ec62a48116135 100644 --- a/drivers/leds/led-class-multicolor.c +++ b/drivers/leds/led-class-multicolor.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -19,9 +20,10 @@ int led_mc_calc_color_components(struct led_classdev_mc *mcled_cdev, int i; for (i = 0; i < mcled_cdev->num_colors; i++) - mcled_cdev->subled_info[i].brightness = brightness * - mcled_cdev->subled_info[i].intensity / - led_cdev->max_brightness; + mcled_cdev->subled_info[i].brightness = + DIV_ROUND_CLOSEST(brightness * + mcled_cdev->subled_info[i].intensity, + led_cdev->max_brightness); return 0; } -- 2.40.1