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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B334510F2847 for ; Fri, 27 Mar 2026 15:42:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KZcpr8B3PaBmoHnOtGWTXWHMqb9a0VgQsEloJr2a4+A=; b=26lpbR6R42dh3tHuQlK+cwbfe9 SsPwCLfAoLgMmIk9xfV3hS07NKAMChScUXHVTa/BGsy13mwj+FRdSoRxjohzF/tA9Pr/oqMf5Nt/9 hq3NMVumKLIStII33ZL+HPb5bjL2AQEYNrku9lnIpqbxLETEYs39HN56BA3Ayek2LlpSmP14JKjAH XIyXCbNwm4kGaYJiS2ENX0zY2axq2yxZatWZMLlrTtaz9/YyQnYYrh3bx1AvIkMwb2j83Bd8paR60 ot7uyKxiCNBhi8w7P2SIUFpQ8j/KmHo3AxASrpRlG54E4yGDMOqzna/NPy7f7lfxzNCby2F9Tkfik pzxNc+cg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w69Kl-00000007huH-421z; Fri, 27 Mar 2026 15:42:51 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w69Kj-00000007htr-3Fsp for linux-arm-kernel@lists.infradead.org; Fri, 27 Mar 2026 15:42:50 +0000 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 6CAED35CF; Fri, 27 Mar 2026 08:42:40 -0700 (PDT) Received: from [10.1.196.96] (eglon.cambridge.arm.com [10.1.196.96]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C69043F99C; Fri, 27 Mar 2026 08:42:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1774626166; bh=WKomjFgiI9EWoQTqUByarteYU8HUetB++8qWiidbEjE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=XjE6ZGu25UcMDd9CEYApdI5QoWo1aAlYMk0PR3w+C9b43s9sUDQd+7HHIrsJCgYDl 94EVZeh7IL5KcC075y07B6tuIo7rEtNPE3ycEWVSqoKCvOS/q5EvJaCQMnrJXUZl0m xo43b8eIHD2e+ZxyaQ6KFKjC8cFb9XlttcBEYhNE= Message-ID: <0bcf0a48-fe1b-4132-9181-e8cd9f7cbcc2@arm.com> Date: Fri, 27 Mar 2026 15:42:34 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 01/40] arm_mpam: Ensure in_reset_state is false after applying configuration To: Ben Horgan Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, zengheng4@huawei.com, linux-doc@vger.kernel.org References: <20260313144617.3420416-1-ben.horgan@arm.com> <20260313144617.3420416-2-ben.horgan@arm.com> Content-Language: en-GB From: James Morse In-Reply-To: <20260313144617.3420416-2-ben.horgan@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260327_084249_881849_62D1B547 X-CRM114-Status: GOOD ( 11.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Ben, Zeng, On 13/03/2026 14:45, Ben Horgan wrote: > From: Zeng Heng > > The per-RIS flag, in_reset_state, indicates whether or not the MSC > registers are in reset state, and allows avoiding resetting when they are > already in reset state. However, when mpam_apply_config() updates the > configuration it doesn't update the in_reset_state flag and so even after > the configuration update in_reset_state can be true and mpam_reset_ris() > will skip the actual register restoration on subsequent resets. > > Once resctrl has a MPAM backend it will use resctrl_arch_reset_all_ctrls() > to reset the MSC configuration on unmount and, if the in_reset_state flag > is bogusly true, fail to reset the MSC configuration. The resulting > non-reset MSC configuration can lead to persistent performance restrictions > even after resctrl is unmounted. > > Fix by clearing in_reset_state to false immediately after successful > configuration application, ensuring that the next reset operation > properly restores MSC register defaults. Reviewed-by: James Morse Thanks! James