From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ben Hutchings <bhutchings@solarflare.com>
Subject: Re: [RFC PATCH v2 03/12] ixgbevf: Mailbox communication
Date: Wed, 23 Dec 2009 20:28:08 +0000
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	 <20091218225140.10698.50205.stgit@localhost.localdomain>
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Cc: netdev@vger.kernel.org, gospo@redhat.com,
	Greg Rose <gregory.v.rose@intel.com>
To: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
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On Fri, 2009-12-18 at 14:51 -0800, Jeff Kirsher wrote:
> From: Greg Rose <gregory.v.rose@intel.com>
> 
> The 82599 virtual function device and the master 82599 physical function
> device implement a mailbox utility for communication between the devices
> using some SRAM scratch memory and a doorbell/answering mechanism enabled
> via interrupt and/or polling.  This C module and accompanying header
> file implement the base functions for use of this feature.
[...]
> diff --git a/drivers/net/ixgbevf/mbx.c b/drivers/net/ixgbevf/mbx.c
> new file mode 100644
> index 0000000..a6e81fe
> --- /dev/null
> +++ b/drivers/net/ixgbevf/mbx.c
[...]
> +/**
> + *  ixgbevf_poll_for_msg - Wait for message notification
> + *  @hw: pointer to the HW structure
> + *
> + *  returns 0 if it successfully received a message notification
> + **/
> +static s32 ixgbevf_poll_for_msg(struct ixgbe_hw *hw)
> +{
> +	struct ixgbe_mbx_info *mbx = &hw->mbx;
> +	int countdown = mbx->timeout;
> +
> +	if (!mbx->ops.check_for_msg)
> +		goto out;
[...]

Can this ever be true?  Wouldn't that be a bug?

There are several similar, apparently unnecessary, tests in the
following functions.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.