[Xenomai-help] RTDM question

[Xenomai-help] RTDM question

[Bosko Radivojevic]

What could be the reason of rt_dev_open() returning 0 (zero)?

I can see that device is properly registered. When I start user-space
program, I can see in /proc/xenomai/rtdm/filedes that one file is
open:
Index   Locked  Device          Owner [PID]
0       0       macbdev0        user [306]

But I never reach write function. rt_dev_write() & rt_dev_read() are
returning -1. In API documentation, for rt_dev_open return values
says:
Positive file descriptor value on success, otherwise a negative error code.

Thanks

Re: [Xenomai-help] RTDM question

[Sebastian Smolorz]

Bosko Radivojevic wrote:
> What could be the reason of rt_dev_open() returning 0 (zero)?
> 
> I can see that device is properly registered. When I start user-space
> program, I can see in /proc/xenomai/rtdm/filedes that one file is
> open:
> Index   Locked  Device          Owner [PID]
> 0       0       macbdev0        user [306]
> 
> But I never reach write function. rt_dev_write() & rt_dev_read() are
> returning -1.

Which read and write handlers do you have registered with your device 
(RT/NRT)? From which context do you call the RTDM functions 
(primary/secondary)?

  In API documentation, for rt_dev_open return values
> says:
> Positive file descriptor value on success, otherwise a negative error code.

I think this is a bug in the documentation. Negative values mean errors, 
all other values (including zero) success.

-- 
Sebastian

Re: [Xenomai-help] RTDM question

[Bosko Radivojevic]

On Thu, Apr 17, 2008 at 1:04 PM, Sebastian Smolorz
<smolorz@domain.hid> wrote:

>  Which read and write handlers do you have registered with your device
> (RT/NRT)? From which context do you call the RTDM functions
> (primary/secondary)?

Thanks :) I've registered read & write RT handlers (by mistake) and
called them from secondary domain...

[Xenomai-help] RTDM question

[Perrine Martignoni]

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Hello,

I ask me some questions about RTDM module. Can we open several times the
same driver ? And have several DEV_FILE
I have understood that we don't manage the number Major and Minor. So I
don't see how it works to do that.

Best Regards

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Re: [Xenomai-help] RTDM question

[Jan Kiszka]

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Perrine Martignoni wrote:
> Hello,
> 
> I ask me some questions about RTDM module. Can we open several times the
> same driver ? And have several DEV_FILE
> I have understood that we don't manage the number Major and Minor. So I
> don't see how it works to do that.

You mean that the same driver source is handling multiple RTDM devices?
That is perfectly feasible, just look at the 16550A driver. But we
should also have some tutorial on this soon, check those two files
waiting to be merged into SVN:

http://zarb.org/~trem/tut03-skeleton-drv.c
http://zarb.org/~trem/tut03-skeleton-app.c

Jan


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