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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4974CCA9EC5 for ; Mon, 12 Oct 2026 23:17:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jULzgmU90GwExwiOegz46rYdLgOhwZJMHx733RDhwSw=; b=LS4NY5sLnkI2AsXaxuQZkk+CdY 0YLirE7WTHWT0/cpGpjxOmz2rPs8L+/mBX4amykZgEr5nuHN86b58EyoCW0jxb5+tyJqUoc1nK/qo glWTTSHrjioaJ4mFXT3rWP94ybMz52ZHs5KyfFOSY7PipCYwnOfF5ellB9GmbdrLUjcK+UZj97y18 RBG6igppkwW4LxHy3uaNkeYcYZ0FLXMgW6+9gsTF6zQhAjWqwLVXWMvCeqz24uZ8acFTrwecVygTC K85KOsCVqTvUn6i6NEMRHuleK/QzbhsTSZ1Cqh5utXnaC5M/JhNCI6DcfI5tkgmfC5o6+HbixRoFO qU39Pmug==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xGPGl-0000000BelN-1SYa; Mon, 12 Oct 2026 23:17:23 +0000 Received: from mail-dl1-x122b.google.com ([2607:f8b0:4864:20::122b]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xGPGi-0000000Bekn-3jcc for linux-arm-kernel@lists.infradead.org; Mon, 12 Oct 2026 23:17:22 +0000 Received: by mail-dl1-x122b.google.com with SMTP id a92af1059eb24-15354aa70e8so2563879c88.1 for ; Mon, 12 Oct 2026 16:17:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1791847039; x=1792451839; darn=lists.infradead.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=jULzgmU90GwExwiOegz46rYdLgOhwZJMHx733RDhwSw=; b=SXc8xG0XZ8Sp4OaduL0PaCG4MMnt43GkWzAtV51E5ZTUirShYzLalqAQXWPpnhBwQ/ duh1Hg6EkCaoojSvnuyXGBLpzNMtzB9s/wqDXWgbzTCLyGWPUwPI1sxYBiH98fVEklg/ 4xY2Pqjzq/XAoj8a/aJlrbcQ/B7AJDSVjPLP4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791847039; x=1792451839; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=jULzgmU90GwExwiOegz46rYdLgOhwZJMHx733RDhwSw=; b=Qld51wRHysOoqGeff/eySLQnp84MYzJr4cfNg6siiSz+WwHTjBgmkcNg2IExbL2T8C PIVHzt6LzA1hLGC9RvAau068jYyGVz5m2Ej4whYR+Ows3N28JaopL4hRAApXssndaiNF QUZC4Z8K7zKRdktWmIwzDZDedXnjUVShYFWOjIAyvTvu7LZE6abZbi3GLS9zFyYvJTF2 0xaz4zTlZidfRS0PchwZdSQSNPGWPlA5HmIg9YH6aB2gxf3Wbrf5CgHz6ivVxLTNJXTs 5O6PFsWXay5/IlTqDsBeurmcgdsFOmjnwW+mejIKWeZQ3xRTaE3DEwkt4ZwEYMQVRoEO d3EA== X-Forwarded-Encrypted: i=1; AKwUvBy8NgMvclHLA5hcFx7+zs1XzI/dz40galrkOkdm5YTwa/kEOQ13s6NiTtuCIJ8d6NdqraIgVxIeVIUDnBXA84U+@lists.infradead.org X-Gm-Message-State: AFq9FYI+ZGBhiWNlgjDr8jwu/Z4IT72Nc3r720QTiZ52qzESUGiopsIt XzrtHpWuIq3AIiaCh9QDXBY5bG/3OV4LdxYsppzW5ulWJVWAWX8ldAYejlf6Jm1IUg== X-Gm-Gg: AYBFou1aGbls5b3Gd7a3mjwFMsX7o/SD5Yq8wIdd+P3n8VSnyjsRGA8s2qbyVX9HEIv hfEuelI9WdzfxSRMq1hMuHhAuZSKejsnKmHp84iBvwM0/EVju7ipdMSX5uRXfZAw221IUuzkcDb lnqJw3Xk1Nlx7hmwfioC24jIAU4qYDdVm+MtAGpfKudhu9dbyN7qO+Ozb3kB2/nY8KaR0u+u8pW gVUTKyzwXS5dMwqlh5Tm6XB4SUl1qPEw2Qs+CHq3OVn1UzJH0nWwE1NxxHMv76t4peyQvRmF9ws hJm2Ckm61hGoXPeX2rB+1acs6cNq30WJbDvncB7ZJW+D1wVZ2qehCqBcVMykThPM2OYPxaDrXr5 GHBwBL5cHvDm2Jb/ya6m2Ox3/Q0p3NqIDh70NIu2VktCdmujXH65wbRO5jop7zVA84MA4HTBcP0 9AZ+R3n/9tF06TJvCflHIv+AeoK+R9kGW9KKtGuuOYsYecpjHrUswUTXabPD3yjZABOWffuvbd9 5tp4OBKflbwABmdN5mH3AszTDFkvjUJmfVngHd6m75NZbZl X-Received: by 2002:a05:7022:1703:b0:166:b307:5855 with SMTP id a92af1059eb24-16a4ee7e657mr14543536c88.0.1791847038615; Mon, 12 Oct 2026 16:17:18 -0700 (PDT) Received: from localhost ([2a00:79e0:2e7c:8:4c0f:2208:f55a:d12f]) by smtp.gmail.com with UTF8SMTPSA id a92af1059eb24-169a1becf08sm36095925c88.5.2026.10.12.16.17.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Oct 2026 16:17:17 -0700 (PDT) Date: Mon, 12 Oct 2026 16:17:15 -0700 From: Brian Norris To: Andy Shevchenko Cc: "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-iio@vger.kernel.org, Andy Shevchenko , Alexandre Torgue , Nuno =?iso-8859-1?Q?S=E1?= , Jonathan Cameron , David Lechner , Maxime Coquelin , linux-kernel@vger.kernel.org, Fabrice Gasnier , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3/5] PM: runtime: Propagate last_busy from dependent to dependency Message-ID: References: <20261002230714.507921-1-briannorris@chromium.org> <20261002160309.3.I40c0bc917fa0b13111251844e9a54feb1d9cd7d2@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261012_161720_976473_5CEC69B6 X-CRM114-Status: GOOD ( 42.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org (Note to self: drop linux-stm32@st-md-mailman.stormreply.com from future postings. It's failing hard, and not (AFAICT) just because I'm not subscribed.) On Mon, Oct 12, 2026 at 10:58:24PM +0300, Andy Shevchenko wrote: > On Mon, Oct 05, 2026 at 11:05:28AM -0700, Brian Norris wrote: > > On Sat, Oct 03, 2026 at 06:21:44PM +0300, Andy Shevchenko wrote: > > > On Fri, Oct 02, 2026 at 04:03:07PM -0700, Brian Norris wrote: > > ... > > > > > Cc: Ulf Hansson > > > > > > Can go under the '---' cutter, so it won't pollute the commit message in the > > > Git history. > > > > This is a well-documented convention. > > > > Documentation/process/submitting-patches.rst > > > > If a person has had the opportunity to comment on a patch, but has not > > provided such comments, you may optionally add a ``Cc:`` tag to the patch. > > This tag documents that potentially interested parties have been included in > > the discussion. > > > > I'm directly referencing Ulf's suggestions (Link tag), so I'm also > > making it explicit that I'm CC'ing him. > > This piece of the documentation was written long time ago before we have got > the kernel.org controlled mailing archives (now it's lore.kernel.org). I argue > that this piece is outdated and we need to look at all aspects of the commit > message. Perhaps having one might not lead to the issue, but exempli gratia 20 > is. I still think it should be moved to under '---' to show the good example. Well, it's not 20; it's 1, with a clear reason. So not sure what you're saying. Anyway, I've prepped that for v2. Do you think you could propose a documentation update, if it's really so out-of-date with current practice? FWIW, a quick look at the v7.1..v7.2 git log shows over 10,000 Cc lines that aren't for stable@ or similar, with over 900 different addressees, across roughly 1300 different commits. (For comparison, there are 17,833 commits in v7.1..v7.2.) It seems like you'll have a hard job trying to apply your rule to everybody's changes, especially if it conflicts with the documentation. > > > > Signed-off-by: Brian Norris > > > > --- > > > > > > Cc: ... > > ... > > > > > +/* > > > > + * Propagate last_busy timestamp from one device to another. This can, for > > > > + * example, prevent overactive suspend when a dependency's usage is primarily > > > > + * driven by one of its dependents. > > > > + */ > > ^^^ > > > > But here you already have an outdated ones, no? Why is this not a problem? > > > > The "target" device (a supplier or parent) can't suspend before this > > point, because the dependent device still holds a reference -- so an > > "outdated" last_busy is not relevant yet. The target last_busy *might* > > become relevant after this point, so this is the point at which it needs > > updated (propagated). > > > > That's what I mean in the commit message by: > > > > propagate last_busy timestamps from a dependent device to its > > dependencies any time it may allow a dependency to suspend -- i.e., > > when releasing a refcount for its parent or suppliers. > > > > Please let me know if I should add some clarification somewhere -- > > perhaps also in the comments here on rpm_propagate_last_busy()? Or if > > you see some other problem in the reasoning. > > Perhaps a word to the top function comment? OK, I've tried to factor that into my drafts for an eventual v2. Thanks! Brian