[PATCH] ARM: mvebu: Fix of_clk_get() call in a non sleeping context
Gregory CLEMENT
gregory.clement at free-electrons.com
Thu Mar 10 04:44:26 PST 2016
Hi Russell King,
On mar., mars 08 2016, Russell King - ARM Linux <linux at arm.linux.org.uk> wrote:
> 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.
Thanks for the clarification, I will work on a alternative solutioin.
Gregory
>
> --
> 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.
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
More information about the linux-arm-kernel
mailing list