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RE: RE: Reentrancy of the ecos drivers
- From: "harbonne marc" <marc dot harbonne at silicomp dot fr>
- To: "'Gary Thomas'" <gary at mlbassoc dot com>
- Cc: <ecos-discuss at ecos dot sourceware dot org>
- Date: Tue, 18 Jul 2006 16:39:14 +0200
- Subject: RE: [ECOS] RE: Reentrancy of the ecos drivers
The driver I speak about is the ipaq touch screen present under
/devs/touch/ipaq but my remark concerns also the i82559 ethernet driveror
any other driver, so If I understand it is the responsibility of the
developer to make its own protection if he wants to share the same resource
between two or more tasks ?
It means that theses drivers are not re-entrant ?
Regards
Marc
-----Message d'origine-----
De?: Gary Thomas [mailto:gary@mlbassoc.com]
Envoyé?: mardi 18 juillet 2006 14:26
À?: harbonne marc
Cc?: ecos-discuss@ecos.sourceware.org
Objet?: Re: [ECOS] RE: Reentrancy of the ecos drivers
harbonne marc wrote:
>
>
> Hi all,
>
>
>
> My question is quite general, I cannot see in any ecos drivers provided
with
> the last version of ecos, a way to protect the shared resources.
>
>
>
> As example, if you look at any display driver, we cannot see a semaphore
> that will protect from a second task to access to the resource by
> pre-empting the one which has the resource.
>
>
>
> The only call I can see is a cyg_scheduler_lock and unlock to get/release
> the resource.
>
>
>
> But in many drivers such mechanism does not exist.
>
> Can you tell me why?
In most cases, such resource management (if it's required) is handled
at a level higher than the physical device driver.
What driver(s) are you concerned about?
--
------------------------------------------------------------
Gary Thomas | Consulting for the
MLB Associates | Embedded world
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