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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> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: (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 that this piece is outdated and we need to look at all aspects of the commit 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 Do you think you could propose a documentation update, if it's really so out-of-date with current practice?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