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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 B1BA6C28CC1 for ; Sat, 1 Jun 2019 13:01:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CD08265CF for ; Sat, 1 Jun 2019 13:01:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="HmB0ttk1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727170AbfFANBi (ORCPT ); Sat, 1 Jun 2019 09:01:38 -0400 Received: from mail-it1-f196.google.com ([209.85.166.196]:53413 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbfFANBh (ORCPT ); Sat, 1 Jun 2019 09:01:37 -0400 Received: by mail-it1-f196.google.com with SMTP id m141so20316375ita.3; Sat, 01 Jun 2019 06:01:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=EL5TH2hMWoiZtVZYy6bsOd3s/PXyVs5Seh9sogDRgo8=; b=HmB0ttk1MhgqW/0cXl3XPzMzL4CI9dP8Jcb8mL4XyLDHx3wrdnlYirDqCIWMORY2Mz 5CrrJ1HciCx/37BAlpXy4BkcZoHVFM9XcYL9sn9cvyTLWLSnpqyDWxUkQX4VXUG+BR3S hCBhf+9kjFAzwqmNwb/eI7Ab1kO9ACrkTlCCt8sxcXxonHfbgeip7U5DizmFb8lgC2kP vn9IkDKfBZxFnE5SGO3Tc5M6s/BNaK0DEGb8/VbVMzYLPva8q9lk1eg0IpBB7J5dRPUw T8ZS3Lsuwq6va+DztgPnbR1dCjrWRgruVaSTtH0b8nMHz+ah+ll+FcmA5vUWyg6dmIZI Ddew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=EL5TH2hMWoiZtVZYy6bsOd3s/PXyVs5Seh9sogDRgo8=; b=EZEwZlD7ltEbMrBOBmGjXCCDcaM1Ohxr7ADy2PjcYDqlMXg8cpSeWUqFLv6BMfJyMs qPyT1APuiRYBVxP4VsFW5ry3Aa8Puebpmd8FclHAczqx5hUu+jSNIPyAZW4pmfBAW2t5 vFNwIUIo56TUcDpwVayEa+tyh4WK+dIWGzFTA6FpKaI45MSqDfj2xFpwsOAuxgKwVCYv dzJIK/3+UR2ePeJfpi2QJqD5rCbEl9Ad6DNUlqMrHHsWiFvKnGOsPfIYiVwIKHyYQjuU Nd3G7jYLXXhSCedePKrqe92QCEVjy85ezqebiEwH9AwXkI7zHNSDLq+GVI3D23sN4GvJ MDyQ== X-Gm-Message-State: APjAAAXylPM4GgMBUFMnyqbwfkcEqts/SSHA/uYfdAR9gylWOuJIsfFt n4Wi7rMkoP5Mr3BN7YO2A2c= X-Google-Smtp-Source: APXvYqz7lBkSUf/T6lvzRFN+Eo5IERMTYy2MiQMbZ8bARPCNx5RSpa6Uvjdh2+rSC9CZyha9y2z+Fg== X-Received: by 2002:a24:d945:: with SMTP id p66mr11171733itg.38.1559394096673; Sat, 01 Jun 2019 06:01:36 -0700 (PDT) Received: from [192.168.2.145] ([94.29.35.141]) by smtp.googlemail.com with ESMTPSA id e188sm3003250ioa.3.2019.06.01.06.01.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 01 Jun 2019 06:01:35 -0700 (PDT) Subject: Re: [PATCH v3 0/8] NVIDIA Tegra clocksource driver improvements To: Daniel Lezcano , Peter De Schrijver Cc: Thomas Gleixner , Joseph Lo , Thierry Reding , Jonathan Hunter , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Chauvet References: <20190524153253.28564-1-digetx@gmail.com> <20190531082634.GA6070@pdeschrijver-desktop.Nvidia.com> <26aeb9f0-5eb1-005a-02c1-4d785fe70331@linaro.org> From: Dmitry Osipenko Message-ID: <6909cb87-8583-4ec8-74b7-a6153aec0246@gmail.com> Date: Sat, 1 Jun 2019 16:00:24 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <26aeb9f0-5eb1-005a-02c1-4d785fe70331@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 31.05.2019 23:31, Daniel Lezcano пишет: > On 31/05/2019 14:33, Dmitry Osipenko wrote: >> 31.05.2019 11:26, Peter De Schrijver пишет: >>> On Fri, May 24, 2019 at 06:32:45PM +0300, Dmitry Osipenko wrote: >>>> Hello, >>>> >>>> This series primarily unifies the driver code across all Tegra SoC >>>> generations. In a result the clocksources are allocated per-CPU on >>>> older Tegra's and have a higher rating than the arch-timer, the newer >>>> Tegra210 is getting support for microsecond clocksource and the driver's >>>> code is getting much cleaner. Note that arch-timer usage is discouraged on >>>> all Tegra's due to the time jitter caused by the CPU frequency scaling. >>> >>> I think the limitations are more as follows: >>> >>> Chip timer suffers cpu dvfs jitter can wakeup from cc7 >>> T20 us-timer No Yes >>> T20 twd timer Yes No? >>> T30 us-timer No Yes >>> T30 twd timer Yes No? >>> T114 us-timer No Yes >>> T114 arch timer No Yes >>> T124 us-timer No Yes >>> T124 arch timer No Yes >>> T210 us-timer No Yes >>> T210 arch timer No No >>> T210 clk_m timer No Yes >>> >>> right? >> >> Doesn't arch timer run off the CPU clock? If yes (that's what I >> assumed), then it should be affected by the DVFS. Otherwise I'll lower >> the clocksource's rating for T114/124/132. >> >> TWD can't wake CPU from the power-down state, so it's a solid "No" for >> TWD in the "can wakeup from cc7" column. > > Wouldn't make sense to rename the timer-tegra20.c to timer-tegra.c now ? Wouldn't hurt, given the refreshment that driver is getting lately. I'll include a patch for that in the next revision, thanks.