From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C92F255F2C; Tue, 17 Mar 2026 17:22:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773768139; cv=none; b=O49z8EhDeYnDUgv+gHvDIfSqtA2Q9WGDu7VB8Pl6OkxHurkfPp0IwabTJx0r34DJ25JnIfYJwfDDq2z2K7uQBxy8ukpLZnXe6O0XiLib4CL12xmfteRHAtIGZina0BWJUcz0GL6jv0B9GhDyZwgM7o96TKp3r/YQYcWNtJLBadg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773768139; c=relaxed/simple; bh=jh2gPRot7MNqrfOgDPkLhGxWii5BtLA90rLtEfEs8oo=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=cRTfWcOomcBbGrNAot0b3fcGFzUTa8Nxu2x7ev5ROWgXx0qy7WiYpDGt15VP+EGINTG+95qlKAH0duK69UAlu6DIEvSlE7+/EY1+bHdUGzM/gJOzkXMq1yav3iPmo0NXJLVtg5Nq8ZSqPOmsCY76yMfzI9rYhmZ+IzV2hevZ+MI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4fZzKG34n7zHnGhy; Wed, 18 Mar 2026 01:21:54 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id 556AB40573; Wed, 18 Mar 2026 01:22:14 +0800 (CST) Received: from localhost (10.48.149.62) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 17 Mar 2026 17:22:12 +0000 Date: Tue, 17 Mar 2026 17:22:09 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v6 01/40] arm_mpam: Ensure in_reset_state is false after applying configuration Message-ID: <20260317172209.00001ec9@huawei.com> In-Reply-To: <20260313144617.3420416-2-ben.horgan@arm.com> References: <20260313144617.3420416-1-ben.horgan@arm.com> <20260313144617.3420416-2-ben.horgan@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100009.china.huawei.com (7.191.174.83) To dubpeml500005.china.huawei.com (7.214.145.207) On Fri, 13 Mar 2026 14:45:38 +0000 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. > > Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") > Signed-off-by: Zeng Heng > Acked-by: Ben Horgan > [Horgan: rewrite commit message to not be specific to resctrl unmount] > Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron