From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90002147C74; Thu, 16 May 2024 21:24:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.214.62.61 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715894663; cv=none; b=QlBAsUxHWVVq1T7xRlq6gLDljqN6B3e0HTEqBM7hZlic0b9JwYK4TSonN+cUVPTJ7jTfILB24jN+bhBv37/cY7ktnxh1ib3YWy5k9r+zgDGWyEcuSs4egcJpp7yaqEM3+1eohJi/89iFnmzj99ZCxoMwA3+wk6yfMsXlQ846+bk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715894663; c=relaxed/simple; bh=fhbU3an/e15PDwjFnQlpO/iVx9HuaXgCMdaYynBMhVk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=e+B4/J2pGlZqdUREPYJsEQYmU7aLs8XiwQxdZsXA4J0SSd+aH0oFs5rRvNEvrLj/V4Hhp9kq+og3rqFYID7H27ZJK0yUfJ7xhtJXra4GOQa1BbXltKFTQKA56bY8j1/y3sZQEi4HNwvY72JuPjIlbYq1DSXnyzcixF2LIhiyXhs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de; spf=pass smtp.mailfrom=denx.de; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b=h17qqsgo; arc=none smtp.client-ip=85.214.62.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=denx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b="h17qqsgo" Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id BF38988410; Thu, 16 May 2024 23:24:17 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1715894659; bh=0io0g3AWBQsg1lVWjX0OfURgfAbrBcVZSYkBGvi99/E=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=h17qqsgof+PMaZHBzXY7LZAtE3I3o/cIG5/yp+yPp0HIrVmE5NxXmFKCI6dTMdSnt IKOrAGM8TJQAcvpVpbOzZYqOGzeGZnqF5QGYwtjbUIyDBuJLStjxl/8BoRzhcvFpv2 NDQYZjWtgLpWpfFWPriTS1VffovMM5X8WZRNadeMQzLsSGcclxQgMDnglUt7Qdhsy3 5MLJunCFGwE5D35hlU5glrl5/WD2qxcjCStNOloAlVdAiWufeLcK19Ajl8FZTGO5V2 WDjwGm7gb0uwOgMNPWrXlPFajtqLNuQs7sUUwIZbTQjhtfReJBXcvwR8m1dfShTu7o lopIPNzcDJ8ag== Message-ID: Date: Thu, 16 May 2024 22:01:37 +0200 Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] [RFC] clk: stm32mp1: Keep RNG1 clock always running To: Gatien CHEVALLIER , linux-crypto@vger.kernel.org Cc: =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , Alexandre Torgue , Gabriel Fernandez , Herbert Xu , Maxime Coquelin , Michael Turquette , Olivia Mackall , Rob Herring , Stephen Boyd , Yang Yingliang , linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com References: <20240513220349.183568-1-marex@denx.de> <51951dd4-8e8c-4e67-89f6-6a710022e34f@foss.st.com> <3257e8f8-5bb0-4c75-a3a3-e5685b65de2a@denx.de> <5b39b5b6-7008-4362-a578-3faab87cd23b@foss.st.com> <2eb2b80e-8650-46cf-9d8f-6dd6a884558a@denx.de> Content-Language: en-US From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean On 5/16/24 4:35 PM, Gatien CHEVALLIER wrote: Hi, >>>>>>> What if you add a trace in a random generation function in random.c? >>>>>> >>>>>> Do you have a function name or line number for me ? >>>>> >>>>> I put a trace in _get_random_bytes() in drivers/char/random.c. I'm not >>>>> 100% sure but this should be the entry point when getting a random >>>>> number. >>>> >>>> You're right, there is a read attempt right before the hang, and >>>> __clk_is_enabled() returns 0 in stm32_read_rng() . In fact, it is >>>> the pm_runtime_get_sync() which is returning -EACCES instead of >>>> zero, and this is currently not checked so the failure is not >>>> detected before register access takes place, to register file with >>>> clock disabled, which triggers a hard hang. >>>> >>>> I'll be sending a patch shortly, thanks for this hint ! >>>> >>> >>> Great news, indeed the return code isn't checked. Let's use >>> pm_runtime_resume_and_get(). >> >> Yes please. >> >> I will wonder why we get EACCES though, that basically means we are >> suspending already. Is it safe to return -errno from rng read function >> in that case ? > > The framework expects a function that can return an error code so I > don't see why not. Else the framework would have an issue. > > I still haven't figured out what is happening. > > Could it be that the kernel is getting entropy with hwrng_fillfn() > like it does periodically to feed the entropy pool and it happens at the > same time as your pm test sequence? Possibly. I use script as init which contains basically #!/bin/sh , mount of a few filesystems like dev, proc, sys, and then the pm_test sequence to avoid wasting time booting full userspace. > FYI, I have been running your script with (echo devices > > /sys/power/pm_test) for 5 hours now and haven't been able to reproduce > the issue. Maybe the 'devices' test is not enough and the deeper pm_test states have some sort of impact ? >>>>>>> After this, I'll try to reproduce the issue. >>>>>> >>>>>> If you have a minute to test it on some ST MP15 board, that would >>>>>> be real nice. Thanks ! >>>>> >>>>> I tried to reproduce the issue you're facing on a STM32MP157C-DK2 no >>>>> SCMI on the 6.9-rc7 kernel tag. I uses OP-TEE and TF-A in the >>>>> bootchain >>>>> but this should not have an impact here. >>>>> >>>>> How did you manage to test using "echo core > /sys/power/pm_test"? >>>>> In kernel/power/suspend.c, enter_state(). If the pm_test_level is >>>>> core, >>>>> then an error is fired with the following trace: >>>>> "Unsupported test mode for suspend to idle, please choose >>>>> none/freezer/devices/platform." >>>> >>>> Could this be firmware related ? >>>> >>>>> I've tried using "echo devices > /sys/power/pm_test" so that I can >>>>> at least test that the driver is put to sleep then wakes up. I do not >>>>> reproduce your issue. >>>> >>>> Can you try 'processors' ? >>>> >>> >>> Given this: >>> #ifdef CONFIG_PM_DEBUG >>>          if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) { >>>              pr_warn("Unsupported test mode for suspend to idle >> >> You're supposed to be suspending to 'mem' , not 'idle' . Could that be >> it ? > > Yes you're right, I've been missing that. I do not have "deep" available > in /sys/power/mem_sleep... not upstreamed yet maybe... Have you coded a > PSCI service for this in U-Boot? > > I'm either missing something or I can't reproduce your setup. The PSCI provider in U-Boot has been in place for years, there's no need to code anything, just compile it and that's all: $ make stm32mp15_basic_defconfig && make -j`nproc` This gets you u-boot-spl.stm32 and u-boot.itb as FSBL/SSBL .