[Xenomai-help] Interrupt numbers

[Xenomai-help] Interrupt numbers

[Terry Fryar]

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Using Xenomai 2.60 with 2.6.38 omap kernel on beagleboard xm.  
 
Trying to use a GPIO pin as an interrupt and catch this in a xenomai
userspace program.  Got the GPIO132 pin set as an input and is working fine.
I guess I'll need to set the irq enable register on the omap cpu to enable
it to generate irqs.  Now...what irq number do I use in the xenomai
rt_intr_create() function call??  I'm not sure how the omap gpio interrupts
are mapped to the linux kernel/xenomai stuff??  Can I use what's in the
arch/arm/plat-omap/include/plat/irqs.h header file?  It appears that each
bank of GPIO pins has it's own interrupt number??
 
Thanks!
 

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Re: [Xenomai-help] Interrupt numbers

[Gilles Chanteperdrix]

On 12/23/2011 01:38 AM, Terry Fryar wrote:
> Using Xenomai 2.60 with 2.6.38 omap kernel on beagleboard xm.  
>  
> Trying to use a GPIO pin as an interrupt and catch this in a xenomai
> userspace program.  Got the GPIO132 pin set as an input and is working fine.
> I guess I'll need to set the irq enable register on the omap cpu to enable
> it to generate irqs.  Now...what irq number do I use in the xenomai
> rt_intr_create() function call??  I'm not sure how the omap gpio interrupts
> are mapped to the linux kernel/xenomai stuff??  Can I use what's in the
> arch/arm/plat-omap/include/plat/irqs.h header file?  It appears that each
> bank of GPIO pins has it's own interrupt number??

Xenomai uses the same interrupt numbers as linux. But rt_intr_create is
deprecated in user-space, you should instead write a driver using the
rtdm skin. The enable bit is handled by xenomai when you request the irq
at xenomai level.

-- 
					    Gilles.

Re: [Xenomai-help] Interrupt numbers

[Terry Fryar]

Thanks Gilles!! 

-----Original Message-----
From: Gilles Chanteperdrix [mailto:gilles.chanteperdrix@xenomai.org] 
Sent: Friday, December 23, 2011 3:45 AM
To: Terry Fryar
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] Interrupt numbers

On 12/23/2011 01:38 AM, Terry Fryar wrote:
> Using Xenomai 2.60 with 2.6.38 omap kernel on beagleboard xm.  
>  
> Trying to use a GPIO pin as an interrupt and catch this in a xenomai 
> userspace program.  Got the GPIO132 pin set as an input and is working
fine.
> I guess I'll need to set the irq enable register on the omap cpu to 
> enable it to generate irqs.  Now...what irq number do I use in the 
> xenomai
> rt_intr_create() function call??  I'm not sure how the omap gpio 
> interrupts are mapped to the linux kernel/xenomai stuff??  Can I use 
> what's in the arch/arm/plat-omap/include/plat/irqs.h header file?  It 
> appears that each bank of GPIO pins has it's own interrupt number??

Xenomai uses the same interrupt numbers as linux. But rt_intr_create is
deprecated in user-space, you should instead write a driver using the rtdm
skin. The enable bit is handled by xenomai when you request the irq at
xenomai level.

-- 
					    Gilles.

Re: [Xenomai-help] Interrupt numbers

[Makarand Pradhan]

On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>
> Xenomai uses the same interrupt numbers as linux. But rt_intr_create is
> deprecated in user-space, you should instead write a driver using the
> rtdm skin. The enable bit is handled by xenomai when you request the irq
> at xenomai level.
>
Hi Gilles,

We use rt_intr_create in our code. So I am trying to understand the 
reasons for it being deprecated. So far, I have not been able to see any 
comments in the code regarding the deprecation or anything in the git log.

Can you pl comment on the reasons for deprecating rt_intr_create? Will 
it be removed in the next release?

Rgds,
Makarand.

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Re: [Xenomai-help] Interrupt numbers

[Gilles Chanteperdrix]

On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>
>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create is
>> deprecated in user-space, you should instead write a driver using the
>> rtdm skin. The enable bit is handled by xenomai when you request the irq
>> at xenomai level.
>>
> Hi Gilles,
> 
> We use rt_intr_create in our code. So I am trying to understand the 
> reasons for it being deprecated. So far, I have not been able to see any 
> comments in the code regarding the deprecation or anything in the git log.

Splitting your code between driver and application enforces a clean
separation between the two, which helps maintenance, so is good on the
long run.

> 
> Can you pl comment on the reasons for deprecating rt_intr_create? Will 
> it be removed in the next release?

We never change ABI in a branch, so, all releases in the 2.6 branch are
guaranteed to support the same services as xenomai 2.6.0.

But in xenomai 3.0, rt_intr_create will certainly no longer be available.
-- 
					    Gilles.

Re: [Xenomai-help] Interrupt numbers

[Terry Fryar]

I would imagine it was nice, however, to have a userspace interrupt ISR so
that flaky code could be debugged in userspace before making it into a
driver?

-----Original Message-----
From: xenomai-help-bounces@domain.hid [mailto:xenomai-help-bounces@domain.hid] On
Behalf Of Gilles Chanteperdrix
Sent: Friday, December 23, 2011 9:53 AM
To: Makarand Pradhan
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] Interrupt numbers

On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>
>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create 
>> is deprecated in user-space, you should instead write a driver using 
>> the rtdm skin. The enable bit is handled by xenomai when you request 
>> the irq at xenomai level.
>>
> Hi Gilles,
> 
> We use rt_intr_create in our code. So I am trying to understand the 
> reasons for it being deprecated. So far, I have not been able to see 
> any comments in the code regarding the deprecation or anything in the git
log.

Splitting your code between driver and application enforces a clean
separation between the two, which helps maintenance, so is good on the long
run.

> 
> Can you pl comment on the reasons for deprecating rt_intr_create? Will 
> it be removed in the next release?

We never change ABI in a branch, so, all releases in the 2.6 branch are
guaranteed to support the same services as xenomai 2.6.0.

But in xenomai 3.0, rt_intr_create will certainly no longer be available.
-- 
					    Gilles.

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Xenomai-help mailing list
Xenomai-help@domain.hid
https://mail.gna.org/listinfo/xenomai-help

Re: [Xenomai-help] Interrupt numbers

[Makarand Pradhan]

Thanks.

On 23/12/11 10:53 AM, Gilles Chanteperdrix wrote:
> On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
>> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create is
>>> deprecated in user-space, you should instead write a driver using the
>>> rtdm skin. The enable bit is handled by xenomai when you request the irq
>>> at xenomai level.
>>>
>> Hi Gilles,
>>
>> We use rt_intr_create in our code. So I am trying to understand the
>> reasons for it being deprecated. So far, I have not been able to see any
>> comments in the code regarding the deprecation or anything in the git log.
> Splitting your code between driver and application enforces a clean
> separation between the two, which helps maintenance, so is good on the
> long run.
>
>> Can you pl comment on the reasons for deprecating rt_intr_create? Will
>> it be removed in the next release?
> We never change ABI in a branch, so, all releases in the 2.6 branch are
> guaranteed to support the same services as xenomai 2.6.0.
>
> But in xenomai 3.0, rt_intr_create will certainly no longer be available.


-- 
___________________________________________________________________________
NOTICE OF CONFIDENTIALITY:
This e-mail and any attachments may contain confidential and privileged information.  If you are
not the intended recipient, please notify the sender immediately by return e-mail and delete this
e-mail and any copies.  Any dissemination or use of this information by a person other than the
intended recipient is unauthorized and may be illegal.
_____________________________________________________________________

  

Re: [Xenomai-help] Interrupt numbers

[Philippe Gerum]

On 12/23/2011 05:16 PM, Terry Fryar wrote:
> I would imagine it was nice, however, to have a userspace interrupt ISR so
> that flaky code could be debugged in userspace before making it into a
> driver?
>

Most interrupts are level sensitive these days, which means that you 
cannot safely step into the code which is supposed to ack the source 
device using a debugger, your kernel would be stormed by IRQs before you 
reach the point where the device request is acked. Remember that 
userland always runs with hw interrupts enabled, regardless of the 
domain. Even edge triggered IRQs would not give you any guarantee with 
respect to device timing requirements.

GDB aside, also think about a transition to secondary mode for whatever 
reason while running in userland prior to acking the device: this would 
be another source of unexpected delays in the acknowledge path.

Debugging work is likely to introduce these issues, unless one refrains 
from using anything else than rt_printf() for logging/observing the 
runtime state, but that would not help with level sensitive IRQs anyway.

You may want to handle the main application logic that responds to an 
interrupt in userland through, in which case you need some RTDM driver 
handling the bottom half of real-time interrupts, which would in turn 
unblock a task sleeping on some read() or ioctl(), to process the event 
in userland (i.e. UIO-like for real-time IRQs).

The bottom line is that you want the IRQ to be acknowledged at device 
level from kernel space. Keeping it masked in the PIC while 
transitioning to user-space would be another option, assuming it is not 
shared with the regular kernel (sharing between rt and non-rt would be 
just wrong anyway), if the device permits (infinitely) delayed 
acknowledges, but I would not recommend this. Typically, a user-space 
code can be wiped off at any time, leaving the device in a weird state.

These are the reasons why I have killed the rt_intr_* API in 3.x, it was 
way too easy to shoot oneself in the foot (and believe me, I saw quite a 
few damaged feet in the past years due to this issue). What was missing 
in this API is a clear hint that some user-provided code should live in 
kernel space to ack each particular device controlled from userland. 
Using RTDM to implement such code and synchronize with the application 
logic in userland is a safe, sane and simple solution.

> -----Original Message-----
> From: xenomai-help-bounces@domain.hid [mailto:xenomai-help-bounces@domain.hid] On
> Behalf Of Gilles Chanteperdrix
> Sent: Friday, December 23, 2011 9:53 AM
> To: Makarand Pradhan
> Cc: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] Interrupt numbers
>
> On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
>> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>>
>>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create
>>> is deprecated in user-space, you should instead write a driver using
>>> the rtdm skin. The enable bit is handled by xenomai when you request
>>> the irq at xenomai level.
>>>
>> Hi Gilles,
>>
>> We use rt_intr_create in our code. So I am trying to understand the
>> reasons for it being deprecated. So far, I have not been able to see
>> any comments in the code regarding the deprecation or anything in the git
> log.
>
> Splitting your code between driver and application enforces a clean
> separation between the two, which helps maintenance, so is good on the long
> run.
>
>>
>> Can you pl comment on the reasons for deprecating rt_intr_create? Will
>> it be removed in the next release?
>
> We never change ABI in a branch, so, all releases in the 2.6 branch are
> guaranteed to support the same services as xenomai 2.6.0.
>
> But in xenomai 3.0, rt_intr_create will certainly no longer be available.


-- 
Philippe.

Re: [Xenomai-help] Interrupt numbers

[Terry Fryar]

Yeh, this is the direction we were going anyways, as I really only need the
irq to trigger an unblock in userland.  I've already got a kernel driver
written using xenomai, so moving the irq code into a driver won't be a
stretch!!


-----Original Message-----
From: Philippe Gerum [mailto:rpm@xenomai.org] 
Sent: Friday, December 23, 2011 12:13 PM
To: xenomai@xenomai.org
Cc: terry.fryar@domain.hid
Subject: Re: [Xenomai-help] Interrupt numbers

On 12/23/2011 05:16 PM, Terry Fryar wrote:
> I would imagine it was nice, however, to have a userspace interrupt 
> ISR so that flaky code could be debugged in userspace before making it 
> into a driver?
>

Most interrupts are level sensitive these days, which means that you cannot
safely step into the code which is supposed to ack the source device using a
debugger, your kernel would be stormed by IRQs before you reach the point
where the device request is acked. Remember that userland always runs with
hw interrupts enabled, regardless of the domain. Even edge triggered IRQs
would not give you any guarantee with respect to device timing requirements.

GDB aside, also think about a transition to secondary mode for whatever
reason while running in userland prior to acking the device: this would be
another source of unexpected delays in the acknowledge path.

Debugging work is likely to introduce these issues, unless one refrains from
using anything else than rt_printf() for logging/observing the runtime
state, but that would not help with level sensitive IRQs anyway.

You may want to handle the main application logic that responds to an
interrupt in userland through, in which case you need some RTDM driver
handling the bottom half of real-time interrupts, which would in turn
unblock a task sleeping on some read() or ioctl(), to process the event in
userland (i.e. UIO-like for real-time IRQs).

The bottom line is that you want the IRQ to be acknowledged at device level
from kernel space. Keeping it masked in the PIC while transitioning to
user-space would be another option, assuming it is not shared with the
regular kernel (sharing between rt and non-rt would be just wrong anyway),
if the device permits (infinitely) delayed acknowledges, but I would not
recommend this. Typically, a user-space code can be wiped off at any time,
leaving the device in a weird state.

These are the reasons why I have killed the rt_intr_* API in 3.x, it was way
too easy to shoot oneself in the foot (and believe me, I saw quite a few
damaged feet in the past years due to this issue). What was missing in this
API is a clear hint that some user-provided code should live in kernel space
to ack each particular device controlled from userland. 
Using RTDM to implement such code and synchronize with the application logic
in userland is a safe, sane and simple solution.

> -----Original Message-----
> From: xenomai-help-bounces@domain.hid 
> [mailto:xenomai-help-bounces@domain.hid] On Behalf Of Gilles 
> Chanteperdrix
> Sent: Friday, December 23, 2011 9:53 AM
> To: Makarand Pradhan
> Cc: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] Interrupt numbers
>
> On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
>> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>>
>>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create 
>>> is deprecated in user-space, you should instead write a driver using 
>>> the rtdm skin. The enable bit is handled by xenomai when you request 
>>> the irq at xenomai level.
>>>
>> Hi Gilles,
>>
>> We use rt_intr_create in our code. So I am trying to understand the 
>> reasons for it being deprecated. So far, I have not been able to see 
>> any comments in the code regarding the deprecation or anything in the 
>> git
> log.
>
> Splitting your code between driver and application enforces a clean 
> separation between the two, which helps maintenance, so is good on the 
> long run.
>
>>
>> Can you pl comment on the reasons for deprecating rt_intr_create? 
>> Will it be removed in the next release?
>
> We never change ABI in a branch, so, all releases in the 2.6 branch 
> are guaranteed to support the same services as xenomai 2.6.0.
>
> But in xenomai 3.0, rt_intr_create will certainly no longer be available.


--
Philippe.

Re: [Xenomai-help] Interrupt numbers

[Michael Pustylnik]

Hi Philippe,

I am really sorry for continuing this thread after such a long delay but I just couldn't get to it sooner.

I understand all your points you mentioned describing the rationale behind your decision to eliminate the rt_intr_* API in Xenomai 3.x, and I definitely agree that they are very valid. However, in real life different Xenomai users could have all kinds of different considerations (other than the ones you mentioned) and there might be special reasons for insisting on using the user space interrupt services.

We happen to be one of such users and we have strong reasons to tolerate the potential issues you mentioned in order to achieve our very specific goals by using the rt_intr_* API. (I don't want to waste your time describing those specific goals but believe me there are ones).
Said that, we would face serious problems with upgrading to Xenomai 3.x, while we actually do want to take advantage of it.

So, my question is simple - could you guys consider leaving the existing rt_intr* services in place as a bonus? (You could still say that this is not a recommended way interrupt handling but it's there for backwards compatibility).

Thanks,

 Michael.
 


-----Original Message-----
From: xenomai-help-bounces@domain.hid [mailto:xenomai-help-bounces@domain.hid] On Behalf Of Philippe Gerum
Sent: Friday, December 23, 2011 1:13 PM
To: xenomai@xenomai.org
Subject: Re: [Xenomai-help] Interrupt numbers

On 12/23/2011 05:16 PM, Terry Fryar wrote:
> I would imagine it was nice, however, to have a userspace interrupt ISR so
> that flaky code could be debugged in userspace before making it into a
> driver?
>

Most interrupts are level sensitive these days, which means that you 
cannot safely step into the code which is supposed to ack the source 
device using a debugger, your kernel would be stormed by IRQs before you 
reach the point where the device request is acked. Remember that 
userland always runs with hw interrupts enabled, regardless of the 
domain. Even edge triggered IRQs would not give you any guarantee with 
respect to device timing requirements.

GDB aside, also think about a transition to secondary mode for whatever 
reason while running in userland prior to acking the device: this would 
be another source of unexpected delays in the acknowledge path.

Debugging work is likely to introduce these issues, unless one refrains 
from using anything else than rt_printf() for logging/observing the 
runtime state, but that would not help with level sensitive IRQs anyway.

You may want to handle the main application logic that responds to an 
interrupt in userland through, in which case you need some RTDM driver 
handling the bottom half of real-time interrupts, which would in turn 
unblock a task sleeping on some read() or ioctl(), to process the event 
in userland (i.e. UIO-like for real-time IRQs).

The bottom line is that you want the IRQ to be acknowledged at device 
level from kernel space. Keeping it masked in the PIC while 
transitioning to user-space would be another option, assuming it is not 
shared with the regular kernel (sharing between rt and non-rt would be 
just wrong anyway), if the device permits (infinitely) delayed 
acknowledges, but I would not recommend this. Typically, a user-space 
code can be wiped off at any time, leaving the device in a weird state.

These are the reasons why I have killed the rt_intr_* API in 3.x, it was 
way too easy to shoot oneself in the foot (and believe me, I saw quite a 
few damaged feet in the past years due to this issue). What was missing 
in this API is a clear hint that some user-provided code should live in 
kernel space to ack each particular device controlled from userland. 
Using RTDM to implement such code and synchronize with the application 
logic in userland is a safe, sane and simple solution.

> -----Original Message-----
> From: xenomai-help-bounces@domain.hid [mailto:xenomai-help-bounces@domain.hid] On
> Behalf Of Gilles Chanteperdrix
> Sent: Friday, December 23, 2011 9:53 AM
> To: Makarand Pradhan
> Cc: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] Interrupt numbers
>
> On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
>> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>>
>>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create
>>> is deprecated in user-space, you should instead write a driver using
>>> the rtdm skin. The enable bit is handled by xenomai when you request
>>> the irq at xenomai level.
>>>
>> Hi Gilles,
>>
>> We use rt_intr_create in our code. So I am trying to understand the
>> reasons for it being deprecated. So far, I have not been able to see
>> any comments in the code regarding the deprecation or anything in the git
> log.
>
> Splitting your code between driver and application enforces a clean
> separation between the two, which helps maintenance, so is good on the long
> run.
>
>>
>> Can you pl comment on the reasons for deprecating rt_intr_create? Will
>> it be removed in the next release?
>
> We never change ABI in a branch, so, all releases in the 2.6 branch are
> guaranteed to support the same services as xenomai 2.6.0.
>
> But in xenomai 3.0, rt_intr_create will certainly no longer be available.


-- 
Philippe.

_______________________________________________
Xenomai-help mailing list
Xenomai-help@domain.hid
https://mail.gna.org/listinfo/xenomai-help

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Re: [Xenomai-help] Interrupt numbers

[Philippe Gerum]

On 01/19/2012 08:41 PM, Michael Pustylnik wrote:
> Hi Philippe,
>
> I am really sorry for continuing this thread after such a long delay but I just couldn't get to it sooner.
>
> I understand all your points you mentioned describing the rationale behind your decision to eliminate the rt_intr_* API in Xenomai 3.x, and I definitely agree that they are very valid. However, in real life different Xenomai users could have all kinds of different considerations (other than the ones you mentioned) and there might be special reasons for insisting on using the user space interrupt services.
>
> We happen to be one of such users and we have strong reasons to tolerate the potential issues you mentioned in order to achieve our very specific goals by using the rt_intr_* API. (I don't want to waste your time describing those specific goals but believe me there are ones).
> Said that, we would face serious problems with upgrading to Xenomai 3.x, while we actually do want to take advantage of it.
>
> So, my question is simple - could you guys consider leaving the existing rt_intr* services in place as a bonus? (You could still say that this is not a recommended way interrupt handling but it's there for backwards compatibility).
>

Please don't misunderstand this decision, it is 100% based on real life 
issues involving multiple customer projects, and was not taken lightly. 
The rationale behind it is that most newcomers should be allowed to 
expect all interfaces from the native/alchemy API to implement the 
recommended way of doing things. rt_intr* is completely at odds with 
this implicit rule: it is error-prone, limited to very specific use 
cases, and can lead to blatantly wrong app designs and roadblocks.

The plan is to provide for a basic uio-like mechanism based on a RTDM 
driver for dealing with IRQs in userland. Users who insist on dealing 
with interrupts in userland could use the RTDM/ioctl() interface 
directly to that driver or wrap the deprecated rt_intr_* calls locally 
over it. Using a RTDM driver dedicated to such a peculiar task (and it 
shall be documented that way) could not be a naive decision.

> Thanks,
>
>   Michael.
>
>
>
> -----Original Message-----
> From: xenomai-help-bounces@domain.hid [mailto:xenomai-help-bounces@domain.hid] On Behalf Of Philippe Gerum
> Sent: Friday, December 23, 2011 1:13 PM
> To: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] Interrupt numbers
>
> On 12/23/2011 05:16 PM, Terry Fryar wrote:
>> I would imagine it was nice, however, to have a userspace interrupt ISR so
>> that flaky code could be debugged in userspace before making it into a
>> driver?
>>
>
> Most interrupts are level sensitive these days, which means that you
> cannot safely step into the code which is supposed to ack the source
> device using a debugger, your kernel would be stormed by IRQs before you
> reach the point where the device request is acked. Remember that
> userland always runs with hw interrupts enabled, regardless of the
> domain. Even edge triggered IRQs would not give you any guarantee with
> respect to device timing requirements.
>
> GDB aside, also think about a transition to secondary mode for whatever
> reason while running in userland prior to acking the device: this would
> be another source of unexpected delays in the acknowledge path.
>
> Debugging work is likely to introduce these issues, unless one refrains
> from using anything else than rt_printf() for logging/observing the
> runtime state, but that would not help with level sensitive IRQs anyway.
>
> You may want to handle the main application logic that responds to an
> interrupt in userland through, in which case you need some RTDM driver
> handling the bottom half of real-time interrupts, which would in turn
> unblock a task sleeping on some read() or ioctl(), to process the event
> in userland (i.e. UIO-like for real-time IRQs).
>
> The bottom line is that you want the IRQ to be acknowledged at device
> level from kernel space. Keeping it masked in the PIC while
> transitioning to user-space would be another option, assuming it is not
> shared with the regular kernel (sharing between rt and non-rt would be
> just wrong anyway), if the device permits (infinitely) delayed
> acknowledges, but I would not recommend this. Typically, a user-space
> code can be wiped off at any time, leaving the device in a weird state.
>
> These are the reasons why I have killed the rt_intr_* API in 3.x, it was
> way too easy to shoot oneself in the foot (and believe me, I saw quite a
> few damaged feet in the past years due to this issue). What was missing
> in this API is a clear hint that some user-provided code should live in
> kernel space to ack each particular device controlled from userland.
> Using RTDM to implement such code and synchronize with the application
> logic in userland is a safe, sane and simple solution.
>
>> -----Original Message-----
>> From: xenomai-help-bounces@domain.hid [mailto:xenomai-help-bounces@domain.hid] On
>> Behalf Of Gilles Chanteperdrix
>> Sent: Friday, December 23, 2011 9:53 AM
>> To: Makarand Pradhan
>> Cc: xenomai@xenomai.org
>> Subject: Re: [Xenomai-help] Interrupt numbers
>>
>> On 12/23/2011 04:26 PM, Makarand Pradhan wrote:
>>> On 23/12/11 04:45 AM, Gilles Chanteperdrix wrote:
>>>>
>>>> Xenomai uses the same interrupt numbers as linux. But rt_intr_create
>>>> is deprecated in user-space, you should instead write a driver using
>>>> the rtdm skin. The enable bit is handled by xenomai when you request
>>>> the irq at xenomai level.
>>>>
>>> Hi Gilles,
>>>
>>> We use rt_intr_create in our code. So I am trying to understand the
>>> reasons for it being deprecated. So far, I have not been able to see
>>> any comments in the code regarding the deprecation or anything in the git
>> log.
>>
>> Splitting your code between driver and application enforces a clean
>> separation between the two, which helps maintenance, so is good on the long
>> run.
>>
>>>
>>> Can you pl comment on the reasons for deprecating rt_intr_create? Will
>>> it be removed in the next release?
>>
>> We never change ABI in a branch, so, all releases in the 2.6 branch are
>> guaranteed to support the same services as xenomai 2.6.0.
>>
>> But in xenomai 3.0, rt_intr_create will certainly no longer be available.
>
>


-- 
Philippe.