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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 5DD01C38A2A for ; Fri, 8 May 2020 12:44:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 358992145D for ; Fri, 8 May 2020 12:44:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941874; bh=ntFx9cisOC5WEGR9NgoQJkp5UtAujJ3Z17jpEpWqYz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1O9cc+2ZUjE37kWJkSXkqQrw/Kfvfs6Urn45pm4mBE40DOAISiLP7G5lLSAQhU/YP 8wmY5DU3EKM7Yy4qnEUeN03oJtigkX3DfPtXCnYC4uMyqoYJKw0UoRkbtaFc+ddpUU kI2w17gSTtMKNSI3x63kaqGqY//NkFqo+hbgPBpg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728386AbgEHMod (ORCPT ); Fri, 8 May 2020 08:44:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:42914 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727104AbgEHMo2 (ORCPT ); Fri, 8 May 2020 08:44:28 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 57B152145D; Fri, 8 May 2020 12:44:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941867; bh=ntFx9cisOC5WEGR9NgoQJkp5UtAujJ3Z17jpEpWqYz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hQKrmklLuJ3wHhF7BU8GQb99vahwrEgnEZ78m8cvQISomyobjrQnaSlclIa1W9xMF btxQQLr+aqXO45ez21BORlEPqAdNdPDQApjn6GxlIpa5kgUFqYB5Xj7SFm5hmYGgb+ oChVCBO5MKW7whA+GGf9RCMUl39piB0EXnRDNxyE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxime Ripard , Michael Turquette Subject: [PATCH 4.4 205/312] clk: multiplier: Prevent the multiplier from under / over flowing Date: Fri, 8 May 2020 14:33:16 +0200 Message-Id: <20200508123138.843408939@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200508123124.574959822@linuxfoundation.org> References: <20200508123124.574959822@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maxime Ripard commit 25f77a3aa4cb948666bf8e7fd972533ea487c3bd upstream. In the current multiplier base clock implementation, if the CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the multiplier computed remains within the boundaries of our clock. This means that if the clock we want to reach is below the parent rate, or if the multiplier is above the maximum that we can reach, we will end up with a completely bogus one that the clock cannot achieve. Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock") Signed-off-by: Maxime Ripard Signed-off-by: Michael Turquette Link: lkml.kernel.org/r/1463402840-17062-3-git-send-email-maxime.ripard@free-electrons.com Signed-off-by: Greg Kroah-Hartman --- drivers/clk/clk-multiplier.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) --- a/drivers/clk/clk-multiplier.c +++ b/drivers/clk/clk-multiplier.c @@ -54,14 +54,28 @@ static unsigned long __bestmult(struct c unsigned long *best_parent_rate, u8 width, unsigned long flags) { + struct clk_multiplier *mult = to_clk_multiplier(hw); unsigned long orig_parent_rate = *best_parent_rate; unsigned long parent_rate, current_rate, best_rate = ~0; unsigned int i, bestmult = 0; + unsigned int maxmult = (1 << width) - 1; - if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) - return rate / *best_parent_rate; + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { + bestmult = rate / orig_parent_rate; - for (i = 1; i < ((1 << width) - 1); i++) { + /* Make sure we don't end up with a 0 multiplier */ + if ((bestmult == 0) && + !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS)) + bestmult = 1; + + /* Make sure we don't overflow the multiplier */ + if (bestmult > maxmult) + bestmult = maxmult; + + return bestmult; + } + + for (i = 1; i < maxmult; i++) { if (rate == orig_parent_rate * i) { /* * This is the best case for us if we have a