Locking in the clk API

Saravana Kannan skannan at codeaurora.org
Fri Jan 21 21:56:53 EST 2011

On 01/21/2011 06:24 PM, Colin Cross wrote:
> On Fri, Jan 21, 2011 at 5:53 PM, Saravana Kannan<skannan at codeaurora.org>  wrote:
>> On 01/21/2011 01:32 AM, Russell King - ARM Linux wrote:
>>> On Thu, Jan 20, 2011 at 08:12:45PM -0800, Saravana Kannan wrote:
>>>> In my opinion, the only major reason for needing atomic clk APIs was due
>>>> to device_ops->suspend being atomic. Since that's not the case anymore,
>>>> I really don't see a justification for atomic clocks. Sure, I might have
>>>> missed some exceptions, but in that case we should make the atomic APIs
>>>> an exception (add clk_enable_atomic) and not the norm.
>>> The suspend method has never been atomic.  It has always been able to
>>> sleep.  You're mistaken.
>> I distinctly remember trying to do sleeping stuff inside a .suspend function
>> and have it complain that it's atomic. So, I think you might be mistaken.
>> But I will have to back up my claims. Let me trying to find that info. In
>> the end, one of us will learn something new -- which is good and all that
>> matters.
> platform_driver->suspend and dev_pm_ops->suspend can sleep, but
> dev_pm_ops->suspend_noirq is called after irqs are disabled and can't
> sleep.  Maybe that's what you were using?

The stuff I did was before suspend_noirq was added. Well, at least the 
struct that I was filling up had no suspend_noirq.


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