Re: Interrupt routine accessing i2c bus

[john bogus <bogusemail98230@xxxxxxxxx>]

--- Shakthi Kannan <shakthimaan@xxxxxxxxx> wrote:

> Hi John,
> 
> On 10/5/06, john bogus <bogusemail98230@xxxxxxxxx>
> wrote:
> > Both ISR's and tasklets both run in
> > interrupt context so the i2c drivers need to
> accessed
> > some other way.
> 
> Which Linux kernel are you using?
2.4.20

> 
> What about task_queues running in schedular queue in
> 2.4 Linux
> kernels? They run in process context.
> 
> http://www.xml.com/ldd/chapter/book/ch06.html#t4
> 

Yes, I thought about this, but won't it have the same
kind of latency possibilities as the completion
version (tens of milliseconds)?

> > I was thinking of creating a task with
> > wait_for_completion(&xxx) and having the ISR do a
> > complete(&xxx) to wake the task.
> 
> Or use kernel_thread() and sleep, and let ISR wake
> it up?  USB hub
> thread is an example:
> 
>
http://lxr.linux.no/source/drivers/usb/hub.c?v=2.4.28#L903

this looks like it has possibilities... thanks
> 
> SK
> 
> -- 
> Shakthi Kannan
> http://www.shakthimaan.com
> 
> --
> Kernelnewbies: Help each other learn about the Linux
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> 


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