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From: linux@arm.linux.org.uk (Russell King - ARM Linux)
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 20:50:51 +0000	[thread overview]
Message-ID: <20160308205050.GN19428@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <8760wx3oy4.fsf@free-electrons.com>

On Tue, Mar 08, 2016 at 05:38:11PM +0100, Gregory CLEMENT wrote:
> And from clk_enable comment we have:
> ""
> clk_enable must not sleep, which differentiates it from clk_prepare.  In a
> simple case, clk_enable can be used instead of clk_prepare to ungate a clk
> if the operation will never sleep.
> ""
> 
> Moreoever for me the "must" was to insist to the order of the call no to
> the fact that both must be called.

As the author of the clk API, the idea here is that clk_prepare()
should always be called _before_ clk_enable() for any clock: in
other words, getting a clock and then calling clk_enable() on it
is not legal.

CCF presently enforces this - clk_enable() without a preceding
clk_prepare() will return -ESHUTDOWN.

-- 
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

  parent reply	other threads:[~2016-03-08 20:50 UTC|newest]

Thread overview: 9+ 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 15:41 ` Thomas Petazzoni
2016-03-08 16:19   ` Gregory CLEMENT
2016-03-08 16:31     ` Thomas Petazzoni
2016-03-08 16:38       ` Gregory CLEMENT
2016-03-08 16:51         ` Thomas Petazzoni
2016-03-08 20:55           ` Russell King - ARM Linux
2016-03-08 20:50         ` Russell King - ARM Linux [this message]
2016-03-10 12:44           ` Gregory CLEMENT

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