From: Michael Ellerman <mpe@ellerman.id.au>
To: Geert Uytterhoeven <geert+renesas@glider.be>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Bryan Wu <cooloney@gmail.com>, Richard Purdie <rpurdie@rpsys.net>,
Jingoo Han <jg1.han@samsung.com>,
Lee Jones <lee.jones@linaro.org>
Cc: devicetree@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: Re: [1/3] powerpc/pmac: Fix DT refcount imbalance in pmac_pic_probe_oldstyle
Date: Fri, 30 Jan 2015 15:09:04 +1100 (AEDT) [thread overview]
Message-ID: <20150130040904.8F89D1402A7@ozlabs.org> (raw)
In-Reply-To: <1421243519-6257-2-git-send-email-geert+renesas@glider.be>
On Wed, 2015-14-01 at 13:51:57 UTC, Geert Uytterhoeven wrote:
> of_find_node_by_name() calls of_node_put() on its "from" parameter,
> which must not be done on "master", as it's still in use, and will be
> released manually later. This may cause a zero kref refcount.
> Use of_get_child_by_name() instead to fix this.
But of_find_node_by_name() searches *all* nodes, not just the children of the
parameter.
So this is a logic change AFAICS, and I have no idea what machines we'd need to
test on to check it.
So I think an of_node_get(master) would be safer and also fix the refcounting.
cheers
WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org>
To: Benjamin Herrenschmidt
<benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>,
Bryan Wu <cooloney-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Richard Purdie <rpurdie-Fm38FmjxZ/leoWH0uzbU5w@public.gmane.org>,
Jingoo Han <jg1.han-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>,
Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Geert Uytterhoeven
<geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ@public.gmane.org>
Subject: Re: [1/3] powerpc/pmac: Fix DT refcount imbalance in pmac_pic_probe_oldstyle
Date: Fri, 30 Jan 2015 15:09:04 +1100 (AEDT) [thread overview]
Message-ID: <20150130040904.8F89D1402A7@ozlabs.org> (raw)
In-Reply-To: <1421243519-6257-2-git-send-email-geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ@public.gmane.org>
On Wed, 2015-14-01 at 13:51:57 UTC, Geert Uytterhoeven wrote:
> of_find_node_by_name() calls of_node_put() on its "from" parameter,
> which must not be done on "master", as it's still in use, and will be
> released manually later. This may cause a zero kref refcount.
> Use of_get_child_by_name() instead to fix this.
But of_find_node_by_name() searches *all* nodes, not just the children of the
parameter.
So this is a logic change AFAICS, and I have no idea what machines we'd need to
test on to check it.
So I think an of_node_get(master) would be safer and also fix the refcounting.
cheers
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next prev parent reply other threads:[~2015-01-30 4:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-14 13:51 [PATCH 0/3] Use of_get_child_by_name() instead of of_find_node_by_name() Geert Uytterhoeven
2015-01-14 13:51 ` [PATCH 1/3] powerpc/pmac: Fix DT refcount imbalance in pmac_pic_probe_oldstyle Geert Uytterhoeven
2015-01-14 13:51 ` Geert Uytterhoeven
2015-01-30 4:09 ` Michael Ellerman [this message]
2015-01-30 4:09 ` [1/3] " Michael Ellerman
2015-01-30 9:00 ` Geert Uytterhoeven
2015-01-30 9:00 ` Geert Uytterhoeven
2015-01-30 9:00 ` Geert Uytterhoeven
2015-02-03 1:12 ` Michael Ellerman
2015-02-03 1:12 ` Michael Ellerman
2015-02-03 1:12 ` Michael Ellerman
2015-01-14 13:51 ` [PATCH 2/3] leds: leds-mc13783: Use of_get_child_by_name() instead of refcount hack Geert Uytterhoeven
2015-01-14 18:42 ` Bryan Wu
[not found] ` <1421243519-6257-1-git-send-email-geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ@public.gmane.org>
2015-01-14 13:51 ` [PATCH 3/3] backlight: 88pm860x_bl: " Geert Uytterhoeven
2015-01-14 13:51 ` Geert Uytterhoeven
2015-01-14 13:51 ` Geert Uytterhoeven
[not found] ` <1421243519-6257-4-git-send-email-geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ@public.gmane.org>
2015-01-18 12:46 ` Lee Jones
2015-01-18 12:46 ` Lee Jones
2015-01-18 12:46 ` Lee Jones
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