how to process data recvd from a device that wont give interrupts

[Kshemendra KP]

softirqs and tasklets run in interrupt context and must not sleep.
One cannot use copy_from_user() and copy_to_user() in both of them.


Regards

Kshemendra



On Fri, Oct 5, 2012 at 10:24 AM, devendra.aaru <devendra.aaru at gmail.com>wrote:

> On Thu, Oct 4, 2012 at 1:50 PM, Mulyadi Santosa
> <mulyadi.santosa at gmail.com> wrote:
> > Hi...
> >
> > On Thu, Oct 4, 2012 at 7:03 PM, devendra.aaru <devendra.aaru at gmail.com>
> wrote:
> >> Hi all,
> >>
> >> I found that you can use a kernel timer and poll for the hardware
> >> interrupt registers whether the interrupt flag is set or not,
> >>
> >> but this will take atleast some good amount of CPU.
> >
> > yeah, thing is, as you know, timer fires interrupt and CPU will
> > certainly have to service it. So, it's impossible to work around it
> > IMHO
> >
> >> are there any ways other than using the kernel timer?
> >
> > perhaps something less intrusive like creating kernel thread and its
> > function is solely checking register state?
> >
>
> yes, more or less similar to what the kernel timer does, :)
>
> I think actually when i get the data , i am just copying it to my
> local structures,
>
> This job is done in the kernel timer itself, with this itself its
> taking a 10% of cpu
> which is actually too much.
>
> let me try with softirqs, i am going to use tasklets, what do you think ?
> :)
> > --
> > regards,
> >
> > Mulyadi Santosa
> > Freelance Linux trainer and consultant
> >
> > blog: the-hydra.blogspot.com
> > training: mulyaditraining.blogspot.com
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20121005/2eb1b85b/attachment.html