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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AE52C433EF for ; Fri, 24 Jun 2022 16:45:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229851AbiFXQpT (ORCPT ); Fri, 24 Jun 2022 12:45:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229595AbiFXQpS (ORCPT ); Fri, 24 Jun 2022 12:45:18 -0400 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 344BB47549; Fri, 24 Jun 2022 09:45:17 -0700 (PDT) Received: (Authenticated sender: alexandre.belloni@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id C54ADC0005; Fri, 24 Jun 2022 16:45:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1656089116; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8Yof9puEZCThqdywnFFBZccm9TUQN0Wk2gtyzAn9V20=; b=Dq3lTFyxOWlCEqKtGGlOdH/oGnRRx6pLTtK3ckpNEeDpz8bQ7AR3+HheTeWQHWj9Mem0ww wtchoEsWAYGFIYyrHBy5yFhrg63uiB2f0j+aU2png94/hFmMxLXau2vCAzTQfpBPKEjA9P 9itAYU6jFeI7z5rbr9NXan+23pNdgvNZXMuITmkwe6fk0HqDy82x/jqM4/14QaZnrM3E4v OPPfzFB/ncQJ7DoHNA6iNISJd+hga9Tw6hnJa4Iy3SqEDQnj4LjI+VzAgqghK3ZYgYqFwE NAd0IoqTrzWSW6D1E5/O9FXmBdRKH8PGtlGdbZ3u0cS13ZiiCJPswDt3Y5ng+g== From: alexandre.belloni@bootlin.com To: linux-kernel@vger.kernel.org, mat.jonczyk@o2.pl, linux-rtc@vger.kernel.org Cc: Alexandre Belloni , bp@alien8.de, hpa@zytor.com, x86@kernel.org, dave.hansen@linux.intel.com, a.zummo@towertech.it, tglx@linutronix.de, mingo@redhat.com Subject: Re: (subset) [PATCH 1/3] rtc-mc146818-lib: reduce RTC_UIP polling period Date: Fri, 24 Jun 2022 18:45:11 +0200 Message-Id: <165608905386.24026.1966178825029089110.b4-ty@bootlin.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220225215011.861477-2-mat.jonczyk@o2.pl> References: <20220225215011.861477-1-mat.jonczyk@o2.pl> <20220225215011.861477-2-mat.jonczyk@o2.pl> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexandre Belloni On Fri, 25 Feb 2022 22:50:09 +0100, Mateusz Jończyk wrote: > Waiting 1ms every time is not necessary, for example on some AMD boxes > the RTC_UIP bit is documented as being high for around 270 microseconds > in some cases [1], which agreed with experiments on an SB710 > southbridge. So 100us seems optimal. > > This in preparation for mach_get_cmos_time() refactoring. > The functions mc146818_get_time() and mach_get_cmos_time() in > arch/x86/kernel/rtc.c perform the same function and the code is > duplicated. mach_get_cmos_time() is busy waiting for the RTC_UIP > bit to clear, so make mc146818_get_time() more similar to it by reducing > the polling period. > > [...] Applied, thanks! [1/3] rtc-mc146818-lib: reduce RTC_UIP polling period commit: 4b94a798e1ca59f4614f5ff6b94fe0c287412b9b Best regards, -- Alexandre Belloni