linux-kernel - Re: [PATCH 4/7] phy: rockchip-usb: add missing of_node

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Message-ID: <20151118193129.GA48815@google.com>
Date:	Wed, 18 Nov 2015 11:31:29 -0800
From:	Brian Norris <computersforpeace@...il.com>
To:	Heiko Stübner <heiko@...ech.de>
Cc:	Julia Lawall <Julia.Lawall@...6.fr>,
	Kishon Vijay Abraham I <kishon@...com>,
	kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org,
	Russell King - ARM Linux <linux@....linux.org.uk>,
	Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
	Andrew Lunn <andrew@...n.ch>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Jason Cooper <jason@...edaemon.net>
Subject: Re: [PATCH 4/7] phy: rockchip-usb: add missing of_node_put

On Wed, Nov 18, 2015 at 08:27:07PM +0100, Heiko Stübner wrote:
> Am Montag, 16. November 2015, 12:33:17 schrieb Julia Lawall:
> hmm, while I agree that the rockchip phy has an issue in the node lifecycle, 
> I'm not sure that patch fixes it fully.
> 
> It currently iterates over each phy, but would only of_node_put the phy it 
> handled last. So if an error happens on the 3rd phy, the first 2 are already 
> instantiated and would also get removed when the overall probe fails, but 
> their of_node would never be "put".

Note the behavior of of_get_next_child() (and
of_get_next_available_child()); it "Decrements the refcount of prev." So
the loop only keeps a reference for (at most) one node at a time.

I believe Julia's patch is correct. It's possible the commit description
could have made this aspect clearer though, since I was confused about
this at first as well.

Regards,
Brian
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