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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,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 5ABA3C4321D for ; Wed, 22 Aug 2018 03:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08FAA217DF for ; Wed, 22 Aug 2018 03:17:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="PTmIr3BH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08FAA217DF Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728050AbeHVGkH (ORCPT ); Wed, 22 Aug 2018 02:40:07 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:50242 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726469AbeHVGkG (ORCPT ); Wed, 22 Aug 2018 02:40:06 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id w7M3H91B015388; Tue, 21 Aug 2018 22:17:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1534907829; bh=zC9hEUd65AchHZX3jNZ2mDhK0zmeSAZ4iVB/5yBIVus=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=PTmIr3BHRo0anYTL58rFR0wup4BT1LZQUYQzLIA3c2+1oJ0tVyHPtdJC6sGdBztiD p+YkZfdN8EdKgezv/q24htI82xq6cA+n7ZbOT4BSzKs5GfBKu4zVzQnOwlOpiCsE4L jMW/HV0RwQFoRLoTl2Wz+Vb/o/obYCib1G8KteVM= Received: from DFLE100.ent.ti.com (dfle100.ent.ti.com [10.64.6.21]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id w7M3H9po014651; Tue, 21 Aug 2018 22:17:09 -0500 Received: from DFLE102.ent.ti.com (10.64.6.23) by DFLE100.ent.ti.com (10.64.6.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1466.3; Tue, 21 Aug 2018 22:17:09 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE102.ent.ti.com (10.64.6.23) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1466.3 via Frontend Transport; Tue, 21 Aug 2018 22:17:08 -0500 Received: from [128.247.59.203] (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id w7M3H8rx015289; Tue, 21 Aug 2018 22:17:08 -0500 Subject: Re: [PATCH] PM / OPP: Refactor counting of added OPPs for v2 to avoid unsupported OPPs To: Viresh Kumar , "Rafael J . Wysocki" CC: , , Tony Lindgren , Tero Kristo , Nishanth Menon , Stephen Boyd , Keerthy J References: <20180822031035.6937-1-d-gerlach@ti.com> From: Dave Gerlach Message-ID: <7ea15971-6e4e-b8f1-209b-4ca018bc1615@ti.com> Date: Tue, 21 Aug 2018 22:17:08 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180822031035.6937-1-d-gerlach@ti.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 08/21/2018 10:10 PM, Dave Gerlach wrote: > Currently the _of_add_opp_table_v2 call loops through the OPP nodes in > the operating-points-v2 table in the device tree and calls > _opp_add_static_v2 for each to add them to the table. It counts each > iteration through this loop as an added OPP, however on platforms making > use of the opp-supported-hw property, _opp_add_static_v2 does not add > OPPs that are not seen as supported on the platform but still returns > success, as this is valid. Because of this the count variable will > contain the number of OPP nodes in the table in device tree but not > necessarily the ones that are supported and actually added. > > As this count value is what is checked to determine if there are any > valid OPPs, if a platform has an operating-points-v2 table with all OPP > nodes containing opp-supported-hw values that are not currently > supported then _of_add_opp_table_v2 will fail to abort as it should due > to an empty table. > > Additionally, since commit 3ba98324e81a ("PM / OPP: Get > performance state using genpd helper"), the same count variable is > compared against the number of OPPs containing performance states and > requires that either all or none have pstates set, however in the case > of any opp table that has any entries that do not get added by > _opp_add_static_v2 due to incompatible opp-supported-hw fields, these > numbers will not match and _of_add_opp_table_v2 will incorrectly fail. > > In order to ensure the count variable reflects the number of OPPs > actually in the table, increment it during the existing loop which walks > the opp table to check if pstate is set and then use that for the > aforementioned checks. > > Fixes: 3ba98324e81a ("PM / OPP: Get performance state using genpd helper") > Signed-off-by: Dave Gerlach > --- This is needed to fix cpufreq probe on TI am335x platforms. Seems that arch/arm/boot/dts/am33xx.dtsi is the only operating-points-v2 table with multiple opp-supported-hw entries which may not all be supported at once, and this caused the count differences that led me here. Regards, Dave > drivers/opp/of.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/opp/of.c b/drivers/opp/of.c > index 7af0ddec936b..f288f83a2e62 100644 > --- a/drivers/opp/of.c > +++ b/drivers/opp/of.c > @@ -399,8 +399,6 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) > > /* We have opp-table node now, iterate over it and add OPPs */ > for_each_available_child_of_node(opp_np, np) { > - count++; > - > ret = _opp_add_static_v2(opp_table, dev, np); > if (ret) { > dev_err(dev, "%s: Failed to add OPP, %d\n", __func__, > @@ -411,15 +409,22 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) > } > } > > + /* > + * Iterate over the list of OPPs that were actually added, as > + * OPPs not supported by the hardware will be ignored by > + * _opp_add_static_v2 above. > + */ > + list_for_each_entry(opp, &opp_table->opp_list, node) { > + count++; > + pstate_count += !!opp->pstate; > + } > + > /* There should be one of more OPP defined */ > if (WARN_ON(!count)) { > ret = -ENOENT; > goto put_opp_table; > } > > - list_for_each_entry(opp, &opp_table->opp_list, node) > - pstate_count += !!opp->pstate; > - > /* Either all or none of the nodes shall have performance state set */ > if (pstate_count && pstate_count != count) { > dev_err(dev, "Not all nodes have performance state set (%d: %d)\n", >