* [Xenomai-help] RTDM and spi
@ 2012-01-05 22:12 Terry Fryar
2012-01-05 22:24 ` Philippe Gerum
0 siblings, 1 reply; 6+ messages in thread
From: Terry Fryar @ 2012-01-05 22:12 UTC (permalink / raw)
To: xenomai
[-- Attachment #1: Type: text/plain, Size: 1701 bytes --]
Using the RTDM api with Xen 2.6 to develop a linux driver.
Basically have an ISR registered using rtdm_irq_request() that is triggered
from a gpio pin. ISR works fine. Inside ISR, the only thing done is a
rtdm_event_signal() on an event.
Then, I have a task created using rtdm_task_init() that is waiting on the
event using rtdm_event_timedwait().
So far, so good...all works. But, in the task I am making an SPI call after
the event is signaled using spi_message_add_tail() and spi_sync() and that's
where I get this:
BUG: sleeping function called from invalid context at kernel/mutex.c:278
[ 98.449178] in_atomic(): 1, irqs_disabled(): 0, pid: -555875760, name:
vÿÿýÿ¿·½ÿ§ÿÿõ>ÿÿýw¿@ÞÞPÞÞ
[ 98.458686] INFO: lockdep is turned off.
[ 98.462811] [<c00572ac>] (unwind_backtrace+0x0/0xe0) from [<c04639bc>]
(mutex_lock_nested+0x24/0x384)
[ 98.472501] [<c04639bc>] (mutex_lock_nested+0x24/0x384) from [<c033ca48>]
(__spi_sync+0x88/0xd8)
[ 98.481730] [<c033ca48>] (__spi_sync+0x88/0xd8) from [<bf007180>]
(irqdrv_task+0x44/0xd4 [irqdrv])
[ 98.491149] [<bf007180>] (irqdrv_task+0x44/0xd4 [irqdrv]) from
[<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c)
[ 98.501845] [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c) from
[<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54)
[ 98.512355] [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54) from [<fff7febf>]
(0xfff7febf)
[ 98.520674] Xenomai: suspending kernel thread bf008180 ('irqdrvTask') at
0xc00a92f8 after exception #0x0
I have tried this inside a kthread and it works fine. I can also try the
spi stuff without being triggered by an IRQ, and I get the same error. I
know this is something simple???
[-- Attachment #2: Type: text/html, Size: 3639 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] RTDM and spi
2012-01-05 22:12 [Xenomai-help] RTDM and spi Terry Fryar
@ 2012-01-05 22:24 ` Philippe Gerum
2012-01-05 22:28 ` Terry Fryar
0 siblings, 1 reply; 6+ messages in thread
From: Philippe Gerum @ 2012-01-05 22:24 UTC (permalink / raw)
To: Terry Fryar; +Cc: xenomai
On 01/05/2012 11:12 PM, Terry Fryar wrote:
> Using the RTDM api with Xen 2.6 to develop a linux driver.
> Basically have an ISR registered using *rtdm_irq_request*()that is
> triggered from a gpio pin. ISR works fine. Inside ISR, the only thing
> done is a *rtdm_event_signal*() on an event.
> Then, I have a task created using *rtdm_task_init*() that is waiting on
> the event using *rtdm_event_timedwait*().
> So far, so good...all works. But, in the task I am making an SPI call
> after the event is signaled using spi_message_add_tail() and spi_sync()
> and that's where I get this:
> BUG: sleeping function called from invalid context at kernel/mutex.c:278
> [ 98.449178] in_atomic(): 1, irqs_disabled(): 0, pid: -555875760, name:
> vÿÿýÿ¿·½ÿ§ÿÿõ>ÿÿýw¿@ÞÞPÞÞ
> [ 98.458686] INFO: lockdep is turned off.
> [ 98.462811] [<c00572ac>] (unwind_backtrace+0x0/0xe0) from [<c04639bc>]
> (mutex_lock_nested+0x24/0x384)
> [ 98.472501] [<c04639bc>] (mutex_lock_nested+0x24/0x384) from
> [<c033ca48>] (__spi_sync+0x88/0xd8)
> [ 98.481730] [<c033ca48>] (__spi_sync+0x88/0xd8) from [<bf007180>]
> (irqdrv_task+0x44/0xd4 [irqdrv])
> [ 98.491149] [<bf007180>] (irqdrv_task+0x44/0xd4 [irqdrv]) from
> [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c)
> [ 98.501845] [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c) from
> [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54)
> [ 98.512355] [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54) from
> [<fff7febf>] (0xfff7febf)
> [ 98.520674] Xenomai: suspending kernel thread bf008180 ('irqdrvTask')
> at 0xc00a92f8 after exception #0x0
> I have tried this inside a kthread and it works fine. I can also try the
> spi stuff without being triggered by an IRQ, and I get the same error. I
> know this is something simple???
You may not call the regular Linux kernel routines from a real-time
context. You have two kernels running side by side, Linux and Xenomai,
unsynchronized. Your RTDM driver is entering __spi_sync() over a
non-Linux context, this can't work since that context may have preempted
Linux anywhere, including in the middle of what Linux thinks is an
atomic section.
Any kernel code you want to call from the real-time co-kernel has to be
adapted to support this. Specifically, you cannot run the regular SPI
stack over a real-time RTDM context.
>
>
>
> _______________________________________________
> Xenomai-help mailing list
> Xenomai-help@domain.hid
> https://mail.gna.org/listinfo/xenomai-help
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] RTDM and spi
2012-01-05 22:24 ` Philippe Gerum
@ 2012-01-05 22:28 ` Terry Fryar
2012-01-05 22:43 ` Philippe Gerum
0 siblings, 1 reply; 6+ messages in thread
From: Terry Fryar @ 2012-01-05 22:28 UTC (permalink / raw)
To: 'Philippe Gerum'; +Cc: xenomai
Ah...simple enough! One question though...are the xenomai sync services
items and irq functions available for non-RT kernel threads??
-----Original Message-----
From: Philippe Gerum [mailto:rpm@xenomai.org
Sent: Thursday, January 05, 2012 4:25 PM
To: Terry Fryar
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] RTDM and spi
On 01/05/2012 11:12 PM, Terry Fryar wrote:
> Using the RTDM api with Xen 2.6 to develop a linux driver.
> Basically have an ISR registered using *rtdm_irq_request*()that is
> triggered from a gpio pin. ISR works fine. Inside ISR, the only thing
> done is a *rtdm_event_signal*() on an event.
> Then, I have a task created using *rtdm_task_init*() that is waiting
> on the event using *rtdm_event_timedwait*().
> So far, so good...all works. But, in the task I am making an SPI call
> after the event is signaled using spi_message_add_tail() and
> spi_sync() and that's where I get this:
> BUG: sleeping function called from invalid context at
> kernel/mutex.c:278 [ 98.449178] in_atomic(): 1, irqs_disabled(): 0, pid:
-555875760, name:
> vÿÿýÿ¿·½ÿ§ÿÿõ>ÿÿýw¿@ÞÞPÞÞ
> [ 98.458686] INFO: lockdep is turned off.
> [ 98.462811] [<c00572ac>] (unwind_backtrace+0x0/0xe0) from
> [<c04639bc>]
> (mutex_lock_nested+0x24/0x384)
> [ 98.472501] [<c04639bc>] (mutex_lock_nested+0x24/0x384) from
> [<c033ca48>] (__spi_sync+0x88/0xd8) [ 98.481730] [<c033ca48>]
> (__spi_sync+0x88/0xd8) from [<bf007180>]
> (irqdrv_task+0x44/0xd4 [irqdrv])
> [ 98.491149] [<bf007180>] (irqdrv_task+0x44/0xd4 [irqdrv]) from
> [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c)
> [ 98.501845] [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c) from
> [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54) [ 98.512355] [<c00e5adc>]
> (__xnpod_schedule+0x5cc/0xa54) from [<fff7febf>] (0xfff7febf) [
> 98.520674] Xenomai: suspending kernel thread bf008180 ('irqdrvTask')
> at 0xc00a92f8 after exception #0x0 I have tried this inside a kthread
> and it works fine. I can also try the spi stuff without being
> triggered by an IRQ, and I get the same error. I know this is
> something simple???
You may not call the regular Linux kernel routines from a real-time context.
You have two kernels running side by side, Linux and Xenomai,
unsynchronized. Your RTDM driver is entering __spi_sync() over a non-Linux
context, this can't work since that context may have preempted Linux
anywhere, including in the middle of what Linux thinks is an atomic section.
Any kernel code you want to call from the real-time co-kernel has to be
adapted to support this. Specifically, you cannot run the regular SPI stack
over a real-time RTDM context.
>
>
>
> _______________________________________________
> Xenomai-help mailing list
> Xenomai-help@domain.hid
> https://mail.gna.org/listinfo/xenomai-help
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] RTDM and spi
2012-01-05 22:28 ` Terry Fryar
@ 2012-01-05 22:43 ` Philippe Gerum
2012-01-05 22:53 ` Terry Fryar
0 siblings, 1 reply; 6+ messages in thread
From: Philippe Gerum @ 2012-01-05 22:43 UTC (permalink / raw)
To: Terry Fryar; +Cc: xenomai
On 01/05/2012 11:28 PM, Terry Fryar wrote:
> Ah...simple enough! One question though...are the xenomai sync services
> items and irq functions available for non-RT kernel threads??
IRQ related routines? like request, enable, disable: yes. It's even
recommended to use them in that context actually.
Xenomai blocking services can only be used over a Xenomai thread, that
is a golden rule. Reason: to wait for a sync, the thread has to be held
by the scheduler of the kernel in question while it sleeps. Only Xenomai
threads have the required internal data to allow the Xenomai scheduler
to hold them.
>
> -----Original Message-----
> From: Philippe Gerum [mailto:rpm@xenomai.org]
> Sent: Thursday, January 05, 2012 4:25 PM
> To: Terry Fryar
> Cc: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] RTDM and spi
>
> On 01/05/2012 11:12 PM, Terry Fryar wrote:
>> Using the RTDM api with Xen 2.6 to develop a linux driver.
>> Basically have an ISR registered using *rtdm_irq_request*()that is
>> triggered from a gpio pin. ISR works fine. Inside ISR, the only thing
>> done is a *rtdm_event_signal*() on an event.
>> Then, I have a task created using *rtdm_task_init*() that is waiting
>> on the event using *rtdm_event_timedwait*().
>> So far, so good...all works. But, in the task I am making an SPI call
>> after the event is signaled using spi_message_add_tail() and
>> spi_sync() and that's where I get this:
>> BUG: sleeping function called from invalid context at
>> kernel/mutex.c:278 [ 98.449178] in_atomic(): 1, irqs_disabled(): 0, pid:
> -555875760, name:
>> vÿÿýÿ¿·½ÿ§ÿÿõ>ÿÿýw¿@ÞÞPÞÞ
>> [ 98.458686] INFO: lockdep is turned off.
>> [ 98.462811] [<c00572ac>] (unwind_backtrace+0x0/0xe0) from
>> [<c04639bc>]
>> (mutex_lock_nested+0x24/0x384)
>> [ 98.472501] [<c04639bc>] (mutex_lock_nested+0x24/0x384) from
>> [<c033ca48>] (__spi_sync+0x88/0xd8) [ 98.481730] [<c033ca48>]
>> (__spi_sync+0x88/0xd8) from [<bf007180>]
>> (irqdrv_task+0x44/0xd4 [irqdrv])
>> [ 98.491149] [<bf007180>] (irqdrv_task+0x44/0xd4 [irqdrv]) from
>> [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c)
>> [ 98.501845] [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c) from
>> [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54) [ 98.512355] [<c00e5adc>]
>> (__xnpod_schedule+0x5cc/0xa54) from [<fff7febf>] (0xfff7febf) [
>> 98.520674] Xenomai: suspending kernel thread bf008180 ('irqdrvTask')
>> at 0xc00a92f8 after exception #0x0 I have tried this inside a kthread
>> and it works fine. I can also try the spi stuff without being
>> triggered by an IRQ, and I get the same error. I know this is
>> something simple???
>
> You may not call the regular Linux kernel routines from a real-time context.
> You have two kernels running side by side, Linux and Xenomai,
> unsynchronized. Your RTDM driver is entering __spi_sync() over a non-Linux
> context, this can't work since that context may have preempted Linux
> anywhere, including in the middle of what Linux thinks is an atomic section.
>
> Any kernel code you want to call from the real-time co-kernel has to be
> adapted to support this. Specifically, you cannot run the regular SPI stack
> over a real-time RTDM context.
>
>>
>>
>>
>> _______________________________________________
>> Xenomai-help mailing list
>> Xenomai-help@domain.hid
>> https://mail.gna.org/listinfo/xenomai-help
>
>
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] RTDM and spi
2012-01-05 22:43 ` Philippe Gerum
@ 2012-01-05 22:53 ` Terry Fryar
2012-01-06 8:07 ` Philippe Gerum
0 siblings, 1 reply; 6+ messages in thread
From: Terry Fryar @ 2012-01-05 22:53 UTC (permalink / raw)
To: 'Philippe Gerum'; +Cc: xenomai
So, this would cover the rtdm_event_timedwait(), for example?? This would
*not* work in a non-realtime thread..correct??
-----Original Message-----
From: Philippe Gerum [mailto:rpm@xenomai.org
Sent: Thursday, January 05, 2012 4:44 PM
To: Terry Fryar
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] RTDM and spi
On 01/05/2012 11:28 PM, Terry Fryar wrote:
> Ah...simple enough! One question though...are the xenomai sync
> services items and irq functions available for non-RT kernel threads??
IRQ related routines? like request, enable, disable: yes. It's even
recommended to use them in that context actually.
Xenomai blocking services can only be used over a Xenomai thread, that is a
golden rule. Reason: to wait for a sync, the thread has to be held by the
scheduler of the kernel in question while it sleeps. Only Xenomai threads
have the required internal data to allow the Xenomai scheduler to hold them.
>
> -----Original Message-----
> From: Philippe Gerum [mailto:rpm@xenomai.org]
> Sent: Thursday, January 05, 2012 4:25 PM
> To: Terry Fryar
> Cc: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] RTDM and spi
>
> On 01/05/2012 11:12 PM, Terry Fryar wrote:
>> Using the RTDM api with Xen 2.6 to develop a linux driver.
>> Basically have an ISR registered using *rtdm_irq_request*()that is
>> triggered from a gpio pin. ISR works fine. Inside ISR, the only thing
>> done is a *rtdm_event_signal*() on an event.
>> Then, I have a task created using *rtdm_task_init*() that is waiting
>> on the event using *rtdm_event_timedwait*().
>> So far, so good...all works. But, in the task I am making an SPI call
>> after the event is signaled using spi_message_add_tail() and
>> spi_sync() and that's where I get this:
>> BUG: sleeping function called from invalid context at
>> kernel/mutex.c:278 [ 98.449178] in_atomic(): 1, irqs_disabled(): 0, pid:
> -555875760, name:
>> vÿÿýÿ¿·½ÿ§ÿÿõ>ÿÿýw¿@ÞÞPÞÞ
>> [ 98.458686] INFO: lockdep is turned off.
>> [ 98.462811] [<c00572ac>] (unwind_backtrace+0x0/0xe0) from
>> [<c04639bc>]
>> (mutex_lock_nested+0x24/0x384)
>> [ 98.472501] [<c04639bc>] (mutex_lock_nested+0x24/0x384) from
>> [<c033ca48>] (__spi_sync+0x88/0xd8) [ 98.481730] [<c033ca48>]
>> (__spi_sync+0x88/0xd8) from [<bf007180>]
>> (irqdrv_task+0x44/0xd4 [irqdrv])
>> [ 98.491149] [<bf007180>] (irqdrv_task+0x44/0xd4 [irqdrv]) from
>> [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c)
>> [ 98.501845] [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c) from
>> [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54) [ 98.512355] [<c00e5adc>]
>> (__xnpod_schedule+0x5cc/0xa54) from [<fff7febf>] (0xfff7febf) [
>> 98.520674] Xenomai: suspending kernel thread bf008180 ('irqdrvTask')
>> at 0xc00a92f8 after exception #0x0 I have tried this inside a kthread
>> and it works fine. I can also try the spi stuff without being
>> triggered by an IRQ, and I get the same error. I know this is
>> something simple???
>
> You may not call the regular Linux kernel routines from a real-time
context.
> You have two kernels running side by side, Linux and Xenomai,
> unsynchronized. Your RTDM driver is entering __spi_sync() over a
> non-Linux context, this can't work since that context may have
> preempted Linux anywhere, including in the middle of what Linux thinks is
an atomic section.
>
> Any kernel code you want to call from the real-time co-kernel has to
> be adapted to support this. Specifically, you cannot run the regular
> SPI stack over a real-time RTDM context.
>
>>
>>
>>
>> _______________________________________________
>> Xenomai-help mailing list
>> Xenomai-help@domain.hid
>> https://mail.gna.org/listinfo/xenomai-help
>
>
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] RTDM and spi
2012-01-05 22:53 ` Terry Fryar
@ 2012-01-06 8:07 ` Philippe Gerum
0 siblings, 0 replies; 6+ messages in thread
From: Philippe Gerum @ 2012-01-06 8:07 UTC (permalink / raw)
To: Terry Fryar; +Cc: xenomai
On 01/05/2012 11:53 PM, Terry Fryar wrote:
> So, this would cover the rtdm_event_timedwait(), for example?? This would
> *not* work in a non-realtime thread..correct??
>
Correct.
> -----Original Message-----
> From: Philippe Gerum [mailto:rpm@xenomai.org]
> Sent: Thursday, January 05, 2012 4:44 PM
> To: Terry Fryar
> Cc: xenomai@xenomai.org
> Subject: Re: [Xenomai-help] RTDM and spi
>
> On 01/05/2012 11:28 PM, Terry Fryar wrote:
>> Ah...simple enough! One question though...are the xenomai sync
>> services items and irq functions available for non-RT kernel threads??
>
> IRQ related routines? like request, enable, disable: yes. It's even
> recommended to use them in that context actually.
>
> Xenomai blocking services can only be used over a Xenomai thread, that is a
> golden rule. Reason: to wait for a sync, the thread has to be held by the
> scheduler of the kernel in question while it sleeps. Only Xenomai threads
> have the required internal data to allow the Xenomai scheduler to hold them.
>
>>
>> -----Original Message-----
>> From: Philippe Gerum [mailto:rpm@xenomai.org]
>> Sent: Thursday, January 05, 2012 4:25 PM
>> To: Terry Fryar
>> Cc: xenomai@xenomai.org
>> Subject: Re: [Xenomai-help] RTDM and spi
>>
>> On 01/05/2012 11:12 PM, Terry Fryar wrote:
>>> Using the RTDM api with Xen 2.6 to develop a linux driver.
>>> Basically have an ISR registered using *rtdm_irq_request*()that is
>>> triggered from a gpio pin. ISR works fine. Inside ISR, the only thing
>>> done is a *rtdm_event_signal*() on an event.
>>> Then, I have a task created using *rtdm_task_init*() that is waiting
>>> on the event using *rtdm_event_timedwait*().
>>> So far, so good...all works. But, in the task I am making an SPI call
>>> after the event is signaled using spi_message_add_tail() and
>>> spi_sync() and that's where I get this:
>>> BUG: sleeping function called from invalid context at
>>> kernel/mutex.c:278 [ 98.449178] in_atomic(): 1, irqs_disabled(): 0, pid:
>> -555875760, name:
>>> vÿÿýÿ¿·½ÿ§ÿÿõ>ÿÿýw¿@ÞÞPÞÞ
>>> [ 98.458686] INFO: lockdep is turned off.
>>> [ 98.462811] [<c00572ac>] (unwind_backtrace+0x0/0xe0) from
>>> [<c04639bc>]
>>> (mutex_lock_nested+0x24/0x384)
>>> [ 98.472501] [<c04639bc>] (mutex_lock_nested+0x24/0x384) from
>>> [<c033ca48>] (__spi_sync+0x88/0xd8) [ 98.481730] [<c033ca48>]
>>> (__spi_sync+0x88/0xd8) from [<bf007180>]
>>> (irqdrv_task+0x44/0xd4 [irqdrv])
>>> [ 98.491149] [<bf007180>] (irqdrv_task+0x44/0xd4 [irqdrv]) from
>>> [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c)
>>> [ 98.501845] [<c00e93d0>] (xnarch_thread_trampoline+0x20/0x2c) from
>>> [<c00e5adc>] (__xnpod_schedule+0x5cc/0xa54) [ 98.512355] [<c00e5adc>]
>>> (__xnpod_schedule+0x5cc/0xa54) from [<fff7febf>] (0xfff7febf) [
>>> 98.520674] Xenomai: suspending kernel thread bf008180 ('irqdrvTask')
>>> at 0xc00a92f8 after exception #0x0 I have tried this inside a kthread
>>> and it works fine. I can also try the spi stuff without being
>>> triggered by an IRQ, and I get the same error. I know this is
>>> something simple???
>>
>> You may not call the regular Linux kernel routines from a real-time
> context.
>> You have two kernels running side by side, Linux and Xenomai,
>> unsynchronized. Your RTDM driver is entering __spi_sync() over a
>> non-Linux context, this can't work since that context may have
>> preempted Linux anywhere, including in the middle of what Linux thinks is
> an atomic section.
>>
>> Any kernel code you want to call from the real-time co-kernel has to
>> be adapted to support this. Specifically, you cannot run the regular
>> SPI stack over a real-time RTDM context.
>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Xenomai-help mailing list
>>> Xenomai-help@domain.hid
>>> https://mail.gna.org/listinfo/xenomai-help
>>
>>
>
>
> --
> Philippe.
>
>
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-01-06 8:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-01-05 22:12 [Xenomai-help] RTDM and spi Terry Fryar
2012-01-05 22:24 ` Philippe Gerum
2012-01-05 22:28 ` Terry Fryar
2012-01-05 22:43 ` Philippe Gerum
2012-01-05 22:53 ` Terry Fryar
2012-01-06 8:07 ` Philippe Gerum
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