From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: mvebu: Fix of_clk_get() call in a non sleeping context
Date: Tue, 8 Mar 2016 17:31:34 +0100 [thread overview]
Message-ID: <20160308173134.22a3ad64@free-electrons.com> (raw)
In-Reply-To: <87a8m93pt0.fsf@free-electrons.com>
Hello,
On Tue, 08 Mar 2016 17:19:39 +0100, Gregory CLEMENT wrote:
> OK, so let's only use clk_enable() which can't sleep. On mvebu SoCs
> there is no prepare/unprepare operation for the clock, so trying to use
> clk_prepare_enable() is useless. Especially for this code which is not
> for a random IP but especially for the Armada XP SoC.
>
> If in the future the same logic can be used for a new mvebu SoC which
> need the prepare/unprepare feature, then we will see how to deal with
> it, but I really doubt that it will happen.
I am not sure doing a clk_enable() without a clk_prepare() before it is
legal, and that's why the clk_prepare_enable() helper is widely used.
>From the clk_prepare() comment:
""
In fact clk_prepare must be called before clk_enable.
""
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
linux-arm-kernel@lists.infradead.org,
Lior Amsalem <alior@marvell.com>,
Nadav Haklai <nadavh@marvell.com>, <stable@vger.kernel.org>
Subject: Re: [PATCH] ARM: mvebu: Fix of_clk_get() call in a non sleeping context
Date: Tue, 8 Mar 2016 17:31:34 +0100 [thread overview]
Message-ID: <20160308173134.22a3ad64@free-electrons.com> (raw)
In-Reply-To: <87a8m93pt0.fsf@free-electrons.com>
Hello,
On Tue, 08 Mar 2016 17:19:39 +0100, Gregory CLEMENT wrote:
> OK, so let's only use clk_enable() which can't sleep. On mvebu SoCs
> there is no prepare/unprepare operation for the clock, so trying to use
> clk_prepare_enable() is useless. Especially for this code which is not
> for a random IP but especially for the Armada XP SoC.
>
> If in the future the same logic can be used for a new mvebu SoC which
> need the prepare/unprepare feature, then we will see how to deal with
> it, but I really doubt that it will happen.
I am not sure doing a clk_enable() without a clk_prepare() before it is
legal, and that's why the clk_prepare_enable() helper is widely used.
>From the clk_prepare() comment:
""
In fact clk_prepare must be called before clk_enable.
""
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2016-03-08 16:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-08 14:18 [PATCH] ARM: mvebu: Fix of_clk_get() call in a non sleeping context Gregory CLEMENT
2016-03-08 14:18 ` Gregory CLEMENT
2016-03-08 15:41 ` Thomas Petazzoni
2016-03-08 15:41 ` Thomas Petazzoni
2016-03-08 16:19 ` Gregory CLEMENT
2016-03-08 16:19 ` Gregory CLEMENT
2016-03-08 16:31 ` Thomas Petazzoni [this message]
2016-03-08 16:31 ` Thomas Petazzoni
2016-03-08 16:38 ` Gregory CLEMENT
2016-03-08 16:38 ` Gregory CLEMENT
2016-03-08 16:51 ` Thomas Petazzoni
2016-03-08 16:51 ` Thomas Petazzoni
2016-03-08 20:55 ` Russell King - ARM Linux
2016-03-08 20:55 ` Russell King - ARM Linux
2016-03-08 20:50 ` Russell King - ARM Linux
2016-03-08 20:50 ` Russell King - ARM Linux
2016-03-10 12:44 ` Gregory CLEMENT
2016-03-10 12:44 ` Gregory CLEMENT
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