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 2DC1CC433DF for ; Thu, 4 Jun 2020 09:22:21 +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 F098820738 for ; Thu, 4 Jun 2020 09:22:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Q7aRu8Wj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F098820738 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.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=o8F9evY6SXYcJBXFf4Uryo23sV5FEIRHJBjwoxf2URk=; b=Q7aRu8WjABSL75 /9KXYOXG4hwjewKN9PVTfCoC5H0M35fVb0vHwyfPSy7nqpf70a2ctE3vxI7R1Cue6zs3Zk4CV1UpH VI0tC7ETgf2/kJKHNrPe57uBBS7YdTMHLhiA2G23ZFpmp+m/1mxz2Fgx2UUu55aEhKJwAZ/IL5d7H 7DSPRpxksyoPWajrsfbBNHpq+cLBK5FyjDDqvxzusg8VkZtKEkUqFLPazx04h7M6zyCzsVgKjtQyw yBjjuRaAJ59cTTrMJMeamWBX7HSJNgVbslEgKVmOSh7n1fNZ0qO0Eeq/NqpVa2afyDoa1ke4JGGsS fGMvm5UvDqH7ZoUzJbJQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jgm4q-0007s9-0E; Thu, 04 Jun 2020 09:22:20 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jgm3W-0006Mk-DG for linux-arm-kernel@lists.infradead.org; Thu, 04 Jun 2020 09:21:02 +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 91DBC55D; Thu, 4 Jun 2020 02:20:57 -0700 (PDT) Received: from bogus (unknown [10.37.12.7]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6B4FA3F6CF; Thu, 4 Jun 2020 02:20:55 -0700 (PDT) Date: Thu, 4 Jun 2020 10:20:52 +0100 From: Sudeep Holla To: Jassi Brar Subject: Re: [RFC] dt-bindings: mailbox: add doorbell support to ARM MHU Message-ID: <20200604092052.GD8814@bogus> References: <0a50f0cf5593baeb628dc8606c523665e5e2ae6c.1589519600.git.viresh.kumar@linaro.org> <20200528192005.GA494874@bogus> <20200529040758.kneg2j4n3gxh2rfv@vireshk-i7> <20200603180435.GB23722@bogus> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200604_022058_505291_924EB8F9 X-CRM114-Status: GOOD ( 18.89 ) 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: Rob Herring , Arnd Bergmann , Devicetree List , Viresh Kumar , Linux Kernel Mailing List , Bjorn Andersson , Frank Rowand , linux-arm-kernel 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 Wed, Jun 03, 2020 at 01:32:42PM -0500, Jassi Brar wrote: > On Wed, Jun 3, 2020 at 1:04 PM Sudeep Holla wrote: > > > > On Fri, May 29, 2020 at 09:37:58AM +0530, Viresh Kumar wrote: > > > On 28-05-20, 13:20, Rob Herring wrote: > > > > Whether Linux > > > > requires serializing mailbox accesses is a separate issue. On that side, > > > > it seems silly to not allow driving the h/w in the most efficient way > > > > possible. > > > > > > That's exactly what we are trying to say. The hardware allows us to > > > write all 32 bits in parallel, without any hardware issues, why > > > shouldn't we do that ? The delay (which Sudeep will find out, he is > > > facing issues with hardware access because of lockdown right now) > > > > OK, I was able to access the setup today. I couldn't reach a point > > where I can do measurements as the system just became unusable with > > one physical channel instead of 2 virtual channels as in my patches. > > > > My test was simple. Switch to schedutil and read sensors periodically > > via sysfs. > > > > arm-scmi firmware:scmi: message for 1 is not expected! > > > This sounds like you are not serialising requests on a shared channel. > Can you please also share the patch? OK, I did try with a small patch initially and then realised we must hit issue with mainline as is. Tried and the behaviour is exact same. All I did is removed my patches and use bit[0] as the signal. It doesn't matter as writes to the register are now serialised. Oh, the above message comes when OS times out in advance while firmware continues to process the old request and respond. The trace I sent gives much better view of what's going on. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel