From mboxrd@z Thu Jan  1 00:00:00 1970
From: Miquel Raynal <miquel.raynal@bootlin.com>
Subject: Re: [PATCH 05/12] PCI: aardvark: add suspend to RAM support
Date: Thu, 13 Dec 2018 15:30:00 +0100
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To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Stephen Boyd <sboyd@kernel.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, sudeep.holla@arm.com, Gregory Clement <gregory.clement@bootlin.com>, Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>, Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>, Thomas Petazzoni <thomas.petazzoni@bootlin.com>, Bjorn Helgaas <bhelgaas@google.com>, devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Antoine Tenart <antoine.tenart@bootlin.com>, Maxime Chevallier <maxime.chevallier@bootlin.com>, Nadav Haklai <nadavh@marvell.com>
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Hi Lorenzo,

> > If that's really the case, then I can see how one device and it's
> > children are suspended and the irq for it is disabled but the providing
> > devices (clk, regulator, bus controller, etc.) are still fully active
> > and not suspended but in fact completely usable and able to service
> > interrupts. If that all makes sense, then I would answer the question
> > with a definitive "yes it's all fine" because the clk consumer could be
> > in the NOIRQ phase of its suspend but the clk provider wouldn't have
> > even started suspending yet when clk_disable_unprepare() is called.  
> 
> That's a very good summary and address my concern, I still question this
> patch correctness (and many others that carry out clk operations in S2R
> NOIRQ phase), they may work but do not tell me they are rock solid given
> your accurate summary above.

I understand your concern but I don't see any alternative right now
and a deep rework of the PM core to respect such dependency is not
something that can be done in a reasonable amount of time. With
regard to this constraint, do you think it is worth blocking the
series?


Thanks,
Miquèl