[Xenomai] CONFIG_XENO_OPT_NATIVE_INTR=y

[Xenomai] CONFIG_XENO_OPT_NATIVE_INTR=y

[John Morris]

My Debian kernel packages [1] use Gilles's kernel config snippet [2] for 
Xenomai configuration, where CONFIG_XENO_OPT_NATIVE_INTR is turned off.

Michael Haberler requested [3] that option be turned on to support RT 
parport ISRs [4], presumably since many LinuxCNC and Machinekit users 
attach stepper motor drivers through the parport.

Given the 'one size fits all' approach to these kernel packages, which 
are intended to run on a variety of x86 hardware for a variety of 
applications (not necessarily just Machinekit), is this an appropriate 
option to enable for general use?  Is there a specific reason this is 
turned off in Gilles's configuration?

Thanks-

	John

[1] https://github.com/zultron/kernel-rt-deb
[2] http://www.xenomai.org/pipermail/xenomai/2013-January/027345.html
[3] https://github.com/zultron/kernel-rt-deb/issues/1
[4] http://acadis.org/pages/captain.at/parallel-port-intr-isr

Re: [Xenomai] CONFIG_XENO_OPT_NATIVE_INTR=y

[Philippe Gerum]

On 04/29/2014 06:33 PM, John Morris wrote:
> My Debian kernel packages [1] use Gilles's kernel config snippet [2] for
> Xenomai configuration, where CONFIG_XENO_OPT_NATIVE_INTR is turned off.
>
> Michael Haberler requested [3] that option be turned on to support RT
> parport ISRs [4], presumably since many LinuxCNC and Machinekit users
> attach stepper motor drivers through the parport.
>
> Given the 'one size fits all' approach to these kernel packages, which
> are intended to run on a variety of x86 hardware for a variety of
> applications (not necessarily just Machinekit), is this an appropriate
> option to enable for general use?  Is there a specific reason this is
> turned off in Gilles's configuration?

The reason to turn this off by default is because this interface is 
deprecated, and was dropped from the upcoming 3.x API. The preferred 
(and strongly suggested) way for dealing with interrupts from userland 
is via an RTDM driver, for reliability reasons.

HTH,

-- 
Philippe.

Re: [Xenomai] CONFIG_XENO_OPT_NATIVE_INTR=y

[Gilles Chanteperdrix]

On 04/29/2014 06:44 PM, Philippe Gerum wrote:
> On 04/29/2014 06:33 PM, John Morris wrote:
>> My Debian kernel packages [1] use Gilles's kernel config snippet [2] for
>> Xenomai configuration, where CONFIG_XENO_OPT_NATIVE_INTR is turned off.
>>
>> Michael Haberler requested [3] that option be turned on to support RT
>> parport ISRs [4], presumably since many LinuxCNC and Machinekit users
>> attach stepper motor drivers through the parport.
>>
>> Given the 'one size fits all' approach to these kernel packages, which
>> are intended to run on a variety of x86 hardware for a variety of
>> applications (not necessarily just Machinekit), is this an appropriate
>> option to enable for general use?  Is there a specific reason this is
>> turned off in Gilles's configuration?
>
> The reason to turn this off by default is because this interface is
> deprecated, and was dropped from the upcoming 3.x API. The preferred
> (and strongly suggested) way for dealing with interrupts from userland
> is via an RTDM driver, for reliability reasons.

Note that we have an in-tree analogy driver for PC parallel port, I do 
not know if it fits Michael needs. The driver seems ported from comedi, 
so it may exist for preempt_rt and rtai as well.

-- 
					    Gilles.