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=-5.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_ADSP_ALL, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EBA7FC4CECE for ; Mon, 14 Oct 2019 13:53:32 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BE8252133F for ; Mon, 14 Oct 2019 13:53:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="GCtM0Jg2"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=megous.com header.i=@megous.com header.b="qeaJSpN7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE8252133F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=megous.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=d4KV+rVvf+OiQZ0uUFaKpjouYN+5wISXIcVBb5n0cpQ=; b=GCtM0Jg2stkw16 wvX/euVHDefkR+Tjc7hQAiWBQjUpHSK3DfqRlFQvcAzlXC3drcBTtu0ciI1iorUy5X39dY3VXQ0Pf LdRCzbHHHKXvAQTm2/VkuVsKDLOgfD4Iqoy+vtU+TwUbf3KCzR6hAPu5J9AVCfj59Sq0u573Ztvxc 3XCdS0vtq8WfDWRMLgnlcvGDwuEJ2pfuEZouCAFT9gLsTsYGk8/8H9pRS/Nb7I11FRrjF3+O0BMng yYC9jof1UsXHshr1UZiJB1EtJfiixCphoA0Ifw3ZiD4UhBXckN6uzxJKiv1iG2uiXMeWxXrLMicN7 C6rQE57wa+Ng7xGiyB6Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iK0mn-0001Id-I5; Mon, 14 Oct 2019 13:53:21 +0000 Received: from vps.xff.cz ([195.181.215.36]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iK0mk-0001Hb-CQ for linux-arm-kernel@lists.infradead.org; Mon, 14 Oct 2019 13:53:20 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1571061192; bh=46QzCIBZ/9atA9i8sP3TsXg10uJJ6p13+mX/uBQH05Y=; h=From:To:Cc:Subject:Date:From; b=qeaJSpN7BUJp2ZteQ5BjyIkVRC6U0UOhE7/gTCpY+DprLpl8kJMvhno9FN5fEXAj/ vqfuwWbW7gK6ALcnPDN5dGh0qLtwAAR92w1PbxUXFpnTl3wx9TeUVdsvoQiTHkucCk 6LgmSYX/mtr2I/n5v+Sbbo87xQkbzlHzWd6xUGPY= From: megous@megous.com To: Subject: [PATCH] pwm: sun4i: Fix incorrect calculation of duty_cycle/period Date: Mon, 14 Oct 2019 15:53:03 +0200 Message-Id: <20191014135303.2944058-1-megous@megous.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191014_065318_591242_F864CBC9 X-CRM114-Status: UNSURE ( 7.78 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ondrej Jirman , "open list:PWM SUBSYSTEM" , open list , Maxime Ripard , Chen-Yu Tsai , Thierry Reding , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , "moderated list:ARM/Allwinner sunXi SoC support" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Ondrej Jirman 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 --- 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); } -- 2.23.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel