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=-2.2 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 612C8C433E0 for ; Thu, 11 Jun 2020 08:40:27 +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 26933207C3 for ; Thu, 11 Jun 2020 08:40:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nlzMTOi+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26933207C3 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=Zj5HoUfFU8waxgMnJjzmQ6/IQlSgG2qKAm9YGvTnD0A=; b=nlzMTOi+DUWlTt XuxP/XqrksSOJ+1MJpjdYNYuXeZ3ext13Khwng2URMnjDqB6N+c/lBPKq4Gd7+SoO8wCmwH71nwRa kOiHo0ANNTiPKuWAk0FeHySuSn7ebWFV0zAYarLj3O1Fk+n93MKPYpuR3TV/W3JF1gIbPJ48M7Qph Cn1WqxELCVadTd1VppO2x5c1jp+yNAUUGFKfAkiMqLj+z/BZa5W6bEW76xrRiUyxVaYpdoMg+asyj c9pKCaDMy5idxQjzMTAjA9G/9OTNerzAU85wyDhSIXELkmJ+/vOHjAlUgoZ1YyyyVXWyybfuwAd7C MdiwY6pkL/dxqAJToa0w==; 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 1jjIl8-000429-H3; Thu, 11 Jun 2020 08:40:26 +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 1jjIl5-00041P-Ef for linux-arm-kernel@lists.infradead.org; Thu, 11 Jun 2020 08:40:24 +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 143F21FB; Thu, 11 Jun 2020 01:40:20 -0700 (PDT) Received: from bogus (unknown [10.37.12.97]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5BA483F73D; Thu, 11 Jun 2020 01:40:17 -0700 (PDT) Date: Thu, 11 Jun 2020 09:40:14 +0100 From: Sudeep Holla To: Jassi Brar Subject: Re: [PATCH] firmware: arm_scmi: fix timeout value for send_message Message-ID: <20200611084014.GB7357@bogus> References: <20200607193023.52344-1-jassisinghbrar@gmail.com> <20200610082315.GB2689@bogus> <20200610155629.GA7357@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-20200611_014023_534693_9260F8ED X-CRM114-Status: GOOD ( 15.03 ) 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@arndb.de" , Viresh Kumar , Linux Kernel Mailing List , Bjorn Andersson , Jassi Brar , Sudeep Holla , 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 10, 2020 at 09:45:55PM -0500, Jassi Brar wrote: > On Wed, Jun 10, 2020 at 10:56 AM Sudeep Holla wrote: > > [I admit you can write bigger posts than me, so I am not going to > write a passionate response to each of your paragraphs. > Let's keep it to the point.] > > > > > > if (xfer->hdr.poll_completion) { > > > > > - ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS); > > > > > + ktime_t stop = ktime_add_ns(ktime_get(), 500 * 1000 * NSEC_PER_USEC); > > > > > > > > > > > > > This is unacceptable delay for schedutil fast_switch. So no for this one. > > > > > > > Increasing timeout does not increase latency. > > > > Agreed, but worst case you may be stuck here for 500ms which is not > > acceptable. > > > Not acceptable to who, you or the kernel? :) Now that you said you > are fixing the scmi's fast_switch implementation. > Sorry, I meant to disable it for single channel implementation. I am not saying we want that on Juno/MHU. > Even though I don't think 500ms would ruin our lives, but ok, I will > make it 30ms - same as you did in the 'else' block. And drop the other > change. I am fine if cpufreq maintainers allow that in the fast switch path that happens in the fast path. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel