From nobody Mon Feb 9 12:38:41 2026 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 A5016C7EE26 for ; Mon, 15 May 2023 16:26:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242681AbjEOQ0g (ORCPT ); Mon, 15 May 2023 12:26:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242501AbjEOQ0d (ORCPT ); Mon, 15 May 2023 12:26:33 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE67A2136; Mon, 15 May 2023 09:26:29 -0700 (PDT) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 34FEdtd7028319; Mon, 15 May 2023 16:26:11 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=qcppdkim1; bh=41opc/0UrQd/HOm8o9Kr2RoTJPOV3lSeWNpIRjNplSw=; b=J11sgL98b0XZeK5XnnfKT+Ml2Zx/IWGgySJPLbvh4t83ki+c+AGQzk4KbVqAlku6RdUf s6Er41Bqp7aCiF+x1i+8IJx/UJQWbt1W+8rIN7Ckyctir0e+LD5cTPt5cIAzOmmH8Z4q n9oXav3V2JNxLLdZILa7ftP4LetBwTX7F0/nLY3k533dZswH/J6XdxR4qogvtwzwCU5d 9eqZ5ePQNdqcGQeaPS3Db5c3fiafxdk95SeJxulTqpxqQmGdUMAZVTi4Yog9qpQslG+D iCDH0uRuZ0YTKzc5zAr1YcLMKAybi4J+1bkp6c/1Lt301Dng4mbHuDwqmvC6wAWnhlFT CQ== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qkgq6se8p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 15 May 2023 16:26:10 +0000 Received: from nalasex01c.na.qualcomm.com (nalasex01c.na.qualcomm.com [10.47.97.35]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 34FGQ9gS014052 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 15 May 2023 16:26:09 GMT Received: from hu-bjorande-lv.qualcomm.com (10.49.16.6) by nalasex01c.na.qualcomm.com (10.47.97.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Mon, 15 May 2023 09:26:09 -0700 From: Bjorn Andersson To: Pavel Machek , Lee Jones , "Anjelique Melendez" CC: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , , , , Caleb Connolly , Steev Klimaszewski Subject: [PATCH v2] leds: qcom-lpg: Fix PWM period limits Date: Mon, 15 May 2023 09:26:04 -0700 Message-ID: <20230515162604.649203-1-quic_bjorande@quicinc.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01b.na.qualcomm.com (10.47.209.197) To nalasex01c.na.qualcomm.com (10.47.97.35) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: 1_n6mVl2ihmA9SLfs40B1k1h90FUV1-y X-Proofpoint-GUID: 1_n6mVl2ihmA9SLfs40B1k1h90FUV1-y X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-15_14,2023-05-05_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=790 clxscore=1011 lowpriorityscore=0 malwarescore=0 priorityscore=1501 impostorscore=0 adultscore=0 mlxscore=0 bulkscore=0 spamscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2305150137 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The introduction of high resolution PWM support changed the order of the operations in the calculation of min and max period. The result in both divisions is in most cases a truncation to 0, which limits the period to the range of [0, 0]. Both numerators (and denominators) are within 64 bits, so the whole expression can be put directly into the div64_u64, instead of doing it partially. Fixes: b00d2ed37617 ("leds: rgb: leds-qcom-lpg: Add support for high resolu= tion PWM") Reviewed-by: Caleb Connolly Tested-by: Steev Klimaszewski Signed-off-by: Bjorn Andersson Acked-by: Lee Jones Tested-by: Johan Hovold Tested-by: Neil Armstrong # on SM8550-QRD --- Changes since v1: - Reworded first sentence to express that it's the order and not the previously non-existent parenthesis that changed... - Picked up review tags. drivers/leds/rgb/leds-qcom-lpg.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-= lpg.c index c9cea797a697..7287fadc00df 100644 --- a/drivers/leds/rgb/leds-qcom-lpg.c +++ b/drivers/leds/rgb/leds-qcom-lpg.c @@ -312,14 +312,14 @@ static int lpg_calc_freq(struct lpg_channel *chan, ui= nt64_t period) max_res =3D LPG_RESOLUTION_9BIT; } =20 - min_period =3D (u64)NSEC_PER_SEC * - div64_u64((1 << pwm_resolution_arr[0]), clk_rate_arr[clk_len - 1]); + min_period =3D div64_u64((u64)NSEC_PER_SEC * (1 << pwm_resolution_arr[0]), + clk_rate_arr[clk_len - 1]); if (period <=3D min_period) return -EINVAL; =20 /* Limit period to largest possible value, to avoid overflows */ - max_period =3D (u64)NSEC_PER_SEC * max_res * LPG_MAX_PREDIV * - div64_u64((1 << LPG_MAX_M), 1024); + max_period =3D div64_u64((u64)NSEC_PER_SEC * max_res * LPG_MAX_PREDIV * (= 1 << LPG_MAX_M), + 1024); if (period > max_period) period =3D max_period; =20 --=20 2.25.1