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SubjectRe: [PATCH] add function spin_event_timeout()
Timur Tabi wrote:
> On Fri, Mar 6, 2009 at 7:11 PM, Roland Dreier <rdreier@cisco.com> wrote:
>
>> > The function spin_event_timeout() takes a condition and timeout value
>> > (in jiffies) as parameters. It spins until either the condition is true
>> > or the timeout expires. It returns non-zero if the condition is true,
>> > zero otherwise.
>>
>> What's the motivation for this? Where do you plan to use it?
>>
>
> I expect it would be useful for drivers that need to wait until a
> specific register has changed its value, but don't want to risk an
> infinite loop if the hardware is not functioning. For example, to
> replace the while loop and subsequent check in this code:
>

A jiffy is a really long time to be spinning, let alone liffies plural.
In this use case are you expecting that the loop will iterate a very
small number of times before returning, and the timeout case is a very
unlikely error condition?

J


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