Date: Tue, 27 Feb 2007 02:18:03 +0000
From: Alan <alan@lxorguk.ukuu.org.uk>
To: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>,
       Arjan van de Ven <arjan@infradead.org>, mingo@redhat.com, akpm@osdl.org,
       linux-kernel@vger.kernel.org
Subject: Re: [patch 0/2] semaphores: add down_interruptible_timeout() and
 asm-generic/semaphore.h
Message-ID: <20070227021803.38c8591f@lxorguk.ukuu.org.uk>
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	<20070227003313.GA7360@infradead.org>
	<200702261654.18005.inaky@linux.intel.com>
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> Yeah, I need semaphore. This is a hw register that says when the hw
> is ready to accept a new command. Code that wants to send commands has
> to down the semaphore and then send it. When hw is ready to get a new
> command, it sends and IRQ and the IRQ up()s the semaphore. 

So you need a mutex not a semaphore
> 
> Now, we don't want to hang on that down() forever if the hw spaces out.
> If we get a timeout, we can try recovery actions (like resetting it,
> for sake of being polite). 

Makes sense but you can also do that with mutexes, and its
mutex_interruptible_timeout() you need I suspect ?

Alan
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