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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 2C434C35242 for ; Fri, 24 Jan 2020 09:40:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E432B2070A for ; Fri, 24 Jan 2020 09:40:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579858813; bh=O9Jvy2TlVkAc+RK8rKlLq3IrIZnt5MgaHxocavlgH/E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kaJdszY5DSEfcX15lOzwB0rhv2WuDAcTDHGTkn+alAUFWbPdNXSRhVDUWLwlIDt2n c5b+Xd/v8d2MRqSTAfOsCKqT09b8SI2R8MLsUs9rjYEL7bijFf7SZSVDEVUW0wX+BJ Yjgu2nO1KiH2+BC5xEaRjeOMP0K7A/g6dluUwJrM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732306AbgAXJkL (ORCPT ); Fri, 24 Jan 2020 04:40:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:37496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732283AbgAXJkK (ORCPT ); Fri, 24 Jan 2020 04:40:10 -0500 Received: from localhost (unknown [145.15.244.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C3C412070A; Fri, 24 Jan 2020 09:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579858809; bh=O9Jvy2TlVkAc+RK8rKlLq3IrIZnt5MgaHxocavlgH/E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2YXIRNqXnO2FVFXu5H9ZJn2vuPm2jtH4w3NmG2/WC1jv9EXZjdCVDTM7D7ZLPC1rH SSE60epRszRin09LeOkZrns5ArvGr1+qkWAuCUJM/XWUq0zDJFM2t1TaYYU0cFefhN OUAvEHoC4VOAfyTyVXLTNNHw0xM7T9XthYELfQRs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ondrej Jirman , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Thierry Reding , Sasha Levin Subject: [PATCH 5.4 062/102] pwm: sun4i: Fix incorrect calculation of duty_cycle/period Date: Fri, 24 Jan 2020 10:31:03 +0100 Message-Id: <20200124092815.700678973@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124092806.004582306@linuxfoundation.org> References: <20200124092806.004582306@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 6f5840a1a82dc..05273725a9fff 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