From: Duncan Sands <baldrick@free.fr>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Writable module parameters - should be volatile?
Date: Sun, 12 Sep 2004 13:57:25 +0200
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I declare a writable module parameter as follows:

static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;

module_param (num_rcv_urbs, uint, S_IRUGO | S_IWUSR);

Shouldn't I declare num_rcv_urbs volatile?  Otherwise compiler
optimizations could (for example) stick it in a register and miss
any changes made by someone writing to it...  However, if I do
declare it volatile then I get a warning:

In function `__check_num_rcv_urbs':
warning: return discards qualifiers from pointer target type

So what is the right thing to do?

Thanks,

Duncan.
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