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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 121D8C33CB1 for ; Thu, 16 Jan 2020 16:50:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D36FB20663 for ; Thu, 16 Jan 2020 16:50:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579193433; bh=TxwKOVFcE2pzmB8eSzLGTN684D6ahhL2WTGB0irJpMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uprlT0v2OgeDG7PTn0V/i3bHBJ1uOZj6QnacqI0JFbZ6kP0NYaPyXBsTkcPPpr2a9 z8fJ6pKBxMGN8tfJ5/N1X6zAmghqlJR/N/UBpFd60T9s9xGwjnn3W/0EFqHQpSEtgW hTjH190P9uYu+UvFsR8LkRVcotiX7FVyR2aGfX98= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729684AbgAPQrb (ORCPT ); Thu, 16 Jan 2020 11:47:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:57326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729464AbgAPQrY (ORCPT ); Thu, 16 Jan 2020 11:47:24 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 24CA32073A; Thu, 16 Jan 2020 16:47:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579193244; bh=TxwKOVFcE2pzmB8eSzLGTN684D6ahhL2WTGB0irJpMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PzMZa/1uCMHSCpC8q61Q87mU/WI8XW++I8IRZK8R6OG6M/fjAnHH1DtNvJ7RhNO77 YUZCPYnFwehTxKJeHrLefpglJ9eVT9fn98CPCzcXf7p1qRaMX+YqCU314Eli8w3H/z /HNCLxLp8g8mIAeLtTBjpSYVdTPSFJ253T+i254I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ondrej Jirman , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Thierry Reding , Sasha Levin , linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 053/205] pwm: sun4i: Fix incorrect calculation of duty_cycle/period Date: Thu, 16 Jan 2020 11:40:28 -0500 Message-Id: <20200116164300.6705-53-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116164300.6705-1-sashal@kernel.org> References: <20200116164300.6705-1-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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ondrej Jirman [ Upstream commit 50cc7e3e4f26e3bf5ed74a8d061195c4d2161b8b ] Since 5.4-rc1, pwm_apply_state calls ->get_state after ->apply if available, and this revealed an issue with integer precision when calculating duty_cycle and period for the currently set state in ->get_state callback. This issue manifested in broken backlight on several Allwinner based devices. Previously this worked, because ->apply updated the passed state directly. Fixes: deb9c462f4e53 ("pwm: sun4i: Don't update the state for the caller of pwm_apply_state") Signed-off-by: Ondrej Jirman Acked-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin --- drivers/pwm/pwm-sun4i.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 6f5840a1a82d..05273725a9ff 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -137,10 +137,10 @@ static void sun4i_pwm_get_state(struct pwm_chip *chip, val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm)); - tmp = prescaler * NSEC_PER_SEC * PWM_REG_DTY(val); + tmp = (u64)prescaler * NSEC_PER_SEC * PWM_REG_DTY(val); state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); - tmp = prescaler * NSEC_PER_SEC * PWM_REG_PRD(val); + tmp = (u64)prescaler * NSEC_PER_SEC * PWM_REG_PRD(val); state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); } -- 2.20.1