Re: Doubt on Interrupt sharing

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Tue, Jul 17, 2007 at 05:26:44PM +0530, Rajendra Stalekar wrote:
> 1. Why is it not correct to install the interrupt handler during driver
> initialization and it's better to install it when we are actually opening
> the device. 

Because you would be servicing interrupts for an unused device. That
wastes:
- - CPU time
- - Memory resources
- - Energy (important for laptop users)

> 2. How can we share the same interrupt line if we install for 2 or more
> devices, when that interrupt is allocated to a particular device ? 

A single interrupt line can be assigned to more than one device.

> I can understand during driver initialization it's not a good idea to
> install the handler because we don't know whether we are going to use the
> device.
> 
> But if we install the handler when the device is opened how can we share the
> interrupt line because it is now dedicated for it.

An dedicated interrupt line for a single device is very uncommon these
days. It used to be normal for ISA, but ISA is dead.


Erik

- -- 
They're all fools. Don't worry. Darwin may be slow, but he'll
eventually get them. -- Matthew Lammers in alt.sysadmin.recovery
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)

iD8DBQFGnLDy/PlVHJtIto0RApY/AJoDfiz8ApSVTWs5e758laKikqomDACfUY8k
YRnZSiz0e6DZhCchTX/FD+I=
=Dvwk
-----END PGP SIGNATURE-----

--
To unsubscribe from this list: send an email with
"unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx
Please read the FAQ at http://kernelnewbies.org/FAQ


[Index of Archives]     [Newbies FAQ]     [Linux Kernel Mentors]     [Linux Kernel Development]     [IETF Annouce]     [Git]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux SCSI]     [Linux ACPI]
  Powered by Linux