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 C9280C4332F for ; Wed, 30 Nov 2022 13:31:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=shsuF7eVPZ5M4ssVThgS31mClSSCLf2h09eqV90UeVo=; b=mIqdLxwrYolP0z koXUKlJVgcb3u8TtyvkLttovyGMjIWGL+KFkaOWyzBOBc7ybv8k7jXcute2r9sVW+alCX4uchNrWg IcN5P7f0WrsV/eeRgCGE/52IcsMdgVaDA9dOOXcz/9A6lcB47AVgwKPvgIBaJI0kP0IXT1arR7dBb RwK2zReQkNP/1OovQu7xuOWsktH536sRqIT1ndiY6TxSWvD4kp6Vl6UBh1xyNJgCD8bqgRduqdIdC gb4bKqRRRmcCp370Y2UsKbsqu8KbJs6ikqlHMPP/Fm2ykIO5OhEnX8NiItwH7ZRbtHQ+SgmkQoNym sQLXGIglcG3IcEjesJiQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p0NA5-00GVSR-LQ; Wed, 30 Nov 2022 13:30:07 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p0N9u-00GVNs-8K for linux-arm-kernel@lists.infradead.org; Wed, 30 Nov 2022 13:29:55 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4C92E61BE2; Wed, 30 Nov 2022 13:29:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D017C433D6; Wed, 30 Nov 2022 13:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669814990; bh=sP2qxHqOzBLVqNoiwojKC0COyARR01VWRMLMQXAbFHs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KFNR8KlKCWZYPbBmoi9ggWRPIauHdC6kTOYCHlWXKGCFcubWTJFeOrCz7f0sNUWcU uA9nt20wyz4yEw+nVtrg8vxiBk8ZXzqtXPzH6LGdyWfeQH1IfkYMiU8937x5ct7vNk nHuyk49wEt6MKfD2pYrRdu6w9JtV2Puj/TIQ+a+dV55w5rLS96wqecsRRM9IWUBgoF 5TvXXtLN7wf7NkMyTH2X6KAdJG3137NhhZx4mB2iqI9QycG+RNiaL2ySfHndq2M2Gs IIIutVLowic/XjbYGz97h2s+fl+piub14eI/FwicshDxWf0loN7QUk9xDgYR6hKXxB lsxNfS8FNI4qQ== Date: Wed, 30 Nov 2022 13:29:45 +0000 From: Will Deacon To: Robin Murphy Cc: Geoff Blake , linux-kernel@vger.kernel.org, catalin.marinas@arm.com, kernel-team@android.com, linux-arm-kernel@lists.infradead.org, Mark Rutland Subject: Re: [PATCH] perf/arm-cmn: Add shutdown routine Message-ID: <20221130132945.GA27624@willie-the-truck> References: <20221125230153.49468-1-blakgeof@amazon.com> <166973320082.112522.10687339610259452670.b4-ty@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221130_052954_392072_E5B3F1C3 X-CRM114-Status: GOOD ( 23.02 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Nov 30, 2022 at 12:28:17PM +0000, Robin Murphy wrote: > On 2022-11-29 19:52, Will Deacon wrote: > > On Fri, 25 Nov 2022 17:01:53 -0600, Geoff Blake wrote: > > > The CMN driver does not gracefully handle all > > > restart cases, such as kexec. On a kexec if the > > > arm-cmn driver is in use it can be left in a state > > > with still active events that can cause spurious and/or > > > unhandled interrupts that appear as non-fatal kernel errors > > > like below, that can be confusing and misleading: > > > > > > [...] > > > > Applied to will (for-next/perf), thanks! > > > > [1/1] perf/arm-cmn: Add shutdown routine > > https://git.kernel.org/will/c/316f862a787c > > Oh, if I'd seen this I'd have said the same thing as when asked about it > off-list, that it's needlessly overcomplicated and doesn't really solve the > problem anyway. If there's a need to be robust against spurious interrupts > then that needs to be done in the interrupt handler. > > Even if we do think it's worth stopping the PMU on shutdown, as we do on > remove, that still only needs a single register write (per the current > remove implementation). Sorry Robin, I didn't spot that you weren't on cc for this. I've dropped the patch locally and I'll update the branches later on today. Please can you help Geoff come up with something better? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel