From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-pm-owner@vger.kernel.org>
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 37278C77B7C
	for <linux-pm@archiver.kernel.org>; Thu, 11 May 2023 06:48:10 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S236570AbjEKGsI (ORCPT <rfc822;linux-pm@archiver.kernel.org>);
        Thu, 11 May 2023 02:48:08 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52602 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S229871AbjEKGsI (ORCPT
        <rfc822;linux-pm@vger.kernel.org>); Thu, 11 May 2023 02:48:08 -0400
Received: from muru.com (muru.com [72.249.23.125])
        by lindbergh.monkeyblade.net (Postfix) with ESMTP id 240E14C13;
        Wed, 10 May 2023 23:48:07 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1])
        by muru.com (Postfix) with ESMTPS id 7F4B0807A;
        Thu, 11 May 2023 06:48:06 +0000 (UTC)
Date:   Thu, 11 May 2023 09:48:05 +0300
From:   Tony Lindgren <tony@atomide.com>
To:     Geert Uytterhoeven <geert+renesas@glider.be>
Cc:     Stephen Boyd <sboyd@kernel.org>,
        Tomasz Figa <tomasz.figa@gmail.com>,
        Sylwester Nawrocki <s.nawrocki@samsung.com>,
        Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        Dejin Zheng <zhengdejin5@gmail.com>,
        Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Nicholas Piggin <npiggin@gmail.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Russell King <linux@armlinux.org.uk>,
        John Stultz <jstultz@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Tero Kristo <tero.kristo@linux.intel.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        linux-arm-kernel@lists.infradead.org,
        linux-renesas-soc@vger.kernel.org, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] iopoll: Do not use timekeeping in
 read_poll_timeout_atomic()
Message-ID: <20230511064805.GF14287@atomide.com>
References: <cover.1683722688.git.geert+renesas@glider.be>
 <8db63020d18fc22e137e4a8f0aa15e6b9949a6f6.1683722688.git.geert+renesas@glider.be>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <8db63020d18fc22e137e4a8f0aa15e6b9949a6f6.1683722688.git.geert+renesas@glider.be>
Precedence: bulk
List-ID: <linux-pm.vger.kernel.org>
X-Mailing-List: linux-pm@vger.kernel.org

Hi,

* Geert Uytterhoeven <geert+renesas@glider.be> [230510 13:23]:
> read_poll_timeout_atomic() uses ktime_get() to implement the timeout
> feature, just like its non-atomic counterpart.  However, there are
> several issues with this, due to its use in atomic contexts:
> 
>   1. When called in the s2ram path (as typically done by clock or PM
>      domain drivers), timekeeping may be suspended, triggering the
>      WARN_ON(timekeeping_suspended) in ktime_get():

Maybe add a comment to read_poll_timeout_atomic() saying it can be
used also with timekeeping_suspended?

Otherwise a few years later it might get broken when somebody goes
to patch it without testing it with timekeeping_suspended :)

Other than that looks good to me:

Reviewed-by: Tony Lindgren <tony@atomide.com>