RE: [ECOS] How to debug synchronisation in the usbs.c in a new usb-driver for the ARM at91sam7s...

["Derek Bouius" <derek dot bouius at sympatico dot ca>]

I just tried implementing it with event flags, and it works fine too, with no noticable performance difference. 

Gary, I have studied the different options but I can't determine why this is a heavier solution. It seems like the only possible
one.
Any other method with condition variables ends up in a race condition deadlock. (Please correct me if I'm wrong though!)

Just doing some more reading about the cyg_drv_cond_wait()... "Note that this function performs an implicit scheduler unlock/relock
sequence, so that it may be used within an explicit cyg_drv_dsr_lock()...cyg_drv_dsr_unlock()  structure."
What if we did the dsr_lock/unlock around the while loop? I'll have to try it.
 
Derek
 

-----Original Message-----
From: oliver munz @ s p e a g [mailto:munz@speag.ch] 
Sent: Thursday, February 16, 2006 11:47 AM
To: Derek Bouius; andrew@lunn.ch
Cc: ecos-discuss@sourceware.org
Subject: Re: [ECOS] How to debug synchronisation in the usbs.c in a new usb-driver for the ARM at91sam7s...

Thanks for the solution...

Does this work whitout kernel? Would it be better to use event-flags?

Thanks
Oliver Munz


----- Original Message ----- 
From: "Derek Bouius" <derek.bouius@sympatico.ca>
To: <andrew@lunn.ch>; <munz@speag.ch>
Cc: <ecos-discuss@sourceware.org>
Sent: Thursday, February 16, 2006 5:15 PM
Subject: Re: [ECOS] How to debug synchronisation in the usbs.c in a new 
usb-driver for the ARM at91sam7s...


>I am not registered for the mailing list, but peruse it once in a while, so 
>I am not sure if my mail will go through to it. Feel
> free to repost it if it doesn't.
> What we did to fix the locking issue was change the mutex to a semaphore. 
> See the patch. It seems to work reliably.
>
> Cheers,
>
> Derek
> 


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