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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07124C433EF for ; Thu, 28 Apr 2022 13:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347692AbiD1NxI (ORCPT ); Thu, 28 Apr 2022 09:53:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230239AbiD1NxG (ORCPT ); Thu, 28 Apr 2022 09:53:06 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2BC85B3C47 for ; Thu, 28 Apr 2022 06:49:52 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E905D1477; Thu, 28 Apr 2022 06:49:51 -0700 (PDT) Received: from e120937-lin (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AEB0A3F5A1; Thu, 28 Apr 2022 06:49:50 -0700 (PDT) Date: Thu, 28 Apr 2022 14:49:48 +0100 From: Cristian Marussi To: Sudeep Holla Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.quinlan@broadcom.com, Jonathan.Cameron@huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com Subject: Re: [PATCH 22/22] firmware: arm_scmi: Add SCMIv3.1 PERFORMANCE_LIMITS_SET checks Message-ID: References: <20220330150551.2573938-1-cristian.marussi@arm.com> <20220330150551.2573938-23-cristian.marussi@arm.com> <20220428131357.mbj5pksrnt5auotb@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220428131357.mbj5pksrnt5auotb@bogus> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 28, 2022 at 02:13:57PM +0100, Sudeep Holla wrote: > On Wed, Mar 30, 2022 at 04:05:51PM +0100, Cristian Marussi wrote: > > Starting with SCMIv3.1, the PERFORMANCE_LIMITS_SET command allows a user > > to request only one between max and min ranges to be changed, while leaving > > the other untouched if set to zero in the request; anyway SCMIv3.1 states > > also explicitly that you cannot leave both of those unchanged (zeroed) when > > issuing such command: add a proper check for this condition. > > > > Signed-off-by: Cristian Marussi > > --- > > drivers/firmware/arm_scmi/perf.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c > > index 65ffda5495d6..8f4051aca220 100644 > > --- a/drivers/firmware/arm_scmi/perf.c > > +++ b/drivers/firmware/arm_scmi/perf.c > > @@ -423,6 +423,9 @@ static int scmi_perf_limits_set(const struct scmi_protocol_handle *ph, > > struct scmi_perf_info *pi = ph->get_priv(ph); > > struct perf_dom_info *dom = pi->dom_info + domain; > > > > + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x3 && !max_perf && !min_perf) > > + return -EINVAL; > > + > > Do we really need the version check here ? I agree it was explicitly added > in v3.1, but it makes sense on any version really. No ? Indeed seemed a silly patch also to me but given that only in v3.1 it is explicitly stated that you cannot issue this command with both min and max ZEROED I though this could have broken older fw that allowed setting PERF_LIMITS_SET max=0 min=0 ....maybe overthought ... Thanks, Cristian