Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Feedback-ID: i56a14606:Fastmail
User-Agent: Cyrus-JMAP/3.9.0-alpha0-415-gf2b17fe6c3-fm-20230503.001-gf2b17fe6
Mime-Version: 1.0
Message-Id: <c6966111-cea0-4547-8463-46f9f767c20f@app.fastmail.com>
In-Reply-To: <CAMuHMdUg0gk3QUmC+OiBDQuZAWdJ2cbPpwaDX+TGoq1EPO1v-A@mail.gmail.com>
References: <cover.1683722688.git.geert+renesas@glider.be>
 <8db63020d18fc22e137e4a8f0aa15e6b9949a6f6.1683722688.git.geert+renesas@glider.be>
 <02ce0541-08cf-4e14-a9b1-c53efea85178@app.fastmail.com>
 <CAMuHMdUg0gk3QUmC+OiBDQuZAWdJ2cbPpwaDX+TGoq1EPO1v-A@mail.gmail.com>
Date:   Wed, 10 May 2023 15:56:39 +0200
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Geert Uytterhoeven" <geert@linux-m68k.org>
Cc:     "Stephen Boyd" <sboyd@kernel.org>,
        "Tomasz Figa" <tomasz.figa@gmail.com>,
        "Sylwester Nawrocki" <s.nawrocki@samsung.com>,
        "Will Deacon" <will@kernel.org>,
        "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>,
        "Tony Lindgren" <tony@atomide.com>,
        "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 <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()
Content-Type: text/plain
Precedence: bulk

On Wed, May 10, 2023, at 15:46, Geert Uytterhoeven wrote:
> I first ran into it when converting open-coded loops to
> read*_poll_timeout_atomic().
> Later, I also saw the issue with the existing
> read*_poll_timeout_atomic() calls in the R-Car SYSC driver, but only
> after applying additional patches from the BSP that impact the moment
> PM Domains are powered during s2ram.

Ok

> The various pointers to existing mitigations in the cover letter should
> give you other suggestions for how to reproduce...

I see the cover letter now, I thought I had looked for it earlier but
didn't notice it.

     Arnd