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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 9AFB3C32751 for ; Wed, 7 Aug 2019 11:56:28 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6D54621922 for ; Wed, 7 Aug 2019 11:56:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="hqeUoYJy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D54621922 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject: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=Guf369dXTm30cb+jnEx0vzvpxpwtdK7XfGaHEYWtlAA=; b=hqeUoYJyHr/yWF rHesc33E2SEjhAPYR4BeRQoByRScA49jhGBXnlTomsn9fceA/2kRfjFMzQnyfZxcouCE47j8xqtr+ iYGH1sHHnNuCUUcRKUtdzp2nHN1e0ZEhpgfl1mdEP4adtdTnQ9iFB/p6vfcJYn9ZtV/nQRUn/1eOf FKorgBCtBKTURptDAD0Y/zUQFnTBFSyFGXaHOWMjHPKJ18RkDLMeE3euSM1Aqh3g24063C4LYEN42 MMJFy/H2Ln8h9q7tbmKNKO+lTHiECtquJYH09bzxFnbIYHmJvgSu3g63JWa6VW7mXgDA5X/HkmlUM 0uGbXbrPjLx+8uo7cOaw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hvKYO-0002H0-2q; Wed, 07 Aug 2019 11:56:28 +0000 Received: from relay4-d.mail.gandi.net ([217.70.183.196]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hvKYL-0002Gf-2j for linux-arm-kernel@lists.infradead.org; Wed, 07 Aug 2019 11:56:26 +0000 X-Originating-IP: 88.168.111.231 Received: from localhost (lpr83-1-88-168-111-231.fbx.proxad.net [88.168.111.231]) (Authenticated sender: maxime.ripard@bootlin.com) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id D8BE3E000D; Wed, 7 Aug 2019 11:56:14 +0000 (UTC) Date: Wed, 7 Aug 2019 13:56:14 +0200 From: Maxime Ripard To: Vasily Khoruzhick Subject: Re: [PATCH] arm64: dts: allwinner: a64: Drop PMU node Message-ID: <20190807115614.phm7sbyae6yajkug@flea> References: <20190806140135.4739-1-anarsoul@gmail.com> <89402d22-d432-9551-e787-c8ede16dbe5f@arm.com> <36e60078-7dd5-9c07-ffa1-6092d8c70fa8@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190807_045625_274219_69870E37 X-CRM114-Status: GOOD ( 21.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree , "Jared D . McNeill" , Chen-Yu Tsai , Rob Herring , Harald Geyer , Robin Murphy , arm-linux Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Aug 06, 2019 at 07:39:26PM -0700, Vasily Khoruzhick wrote: > On Tue, Aug 6, 2019 at 2:14 PM Robin Murphy wrote: > > > > On 2019-08-06 9:52 pm, Vasily Khoruzhick wrote: > > > On Tue, Aug 6, 2019 at 1:19 PM Harald Geyer wrote: > > >> > > >> Vasily Khoruzhick writes: > > >>> On Tue, Aug 6, 2019 at 7:35 AM Robin Murphy wrote: > > >>>> > > >>>> On 06/08/2019 15:01, Vasily Khoruzhick wrote: > > >>>>> Looks like PMU in A64 is broken, it generates no interrupts at all and > > >>>>> as result 'perf top' shows no events. > > >>>> > > >>>> Does something like 'perf stat sleep 1' at least count cycles correctly? > > >>>> It could well just be that the interrupt numbers are wrong... > > >>> > > >>> Looks like it does, at least result looks plausible: > > >> > > >> I'm using perf stat regularly (cache benchmarks) and it works fine. > > >> > > >> Unfortunately I wasn't aware that perf stat is a poor test for > > >> the interrupts part of the node, when I added it. So I'm not too > > >> surprised I got it wrong. > > >> > > >> However, it would be unfortunate if the node got removed completely, > > >> because perf stat would not work anymore. Maybe we can only remove > > >> the interrupts or just fix them even if the HW doesn't work? > > > > > > I'm not familiar with PMU driver. Is it possible to get it working > > > without interrupts? > > > > Yup - you get a grumpy message from the driver, it will refuse sampling > > events (the ones which weren't working anyway), and if you measure > > anything for long enough that a counter overflows you'll get wonky > > results. But for counting hardware events over relatively short periods > > it'll still do the job. > > I tried to drop interrupts completely from the node but 'perf top' is > still broken. Though now in different way: it complains "cycles: PMU > Hardware doesn't support sampling/overflow-interrupts. Try 'perf > stat'" I have no idea if that's the culprit, but what is the state of the 0x09010000 register? (in particular, are the bits 16-19 and 24 set or not? Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel