From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] net/hamradio: fix test in receive()
Date: Tue, 13 Oct 2009 19:10:03 -0700
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Cc: netdev@vger.kernel.org, davem@davemloft.net,
	Thomas Sailer <t.sailer@alumni.ethz.ch>
To: Roel Kluin <roel.kluin@gmail.com>
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On Tue, 06 Oct 2009 13:20:08 +0200 Roel Kluin <roel.kluin@gmail.com> wrote:

> The negation makes it a bool before the comparison and hence it
> will never evaluate to true.
> 
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> ---
> Was this intended?
> 
> diff --git a/drivers/net/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c
> index 7bcaf7c..ee06a13 100644
> --- a/drivers/net/hamradio/baycom_epp.c
> +++ b/drivers/net/hamradio/baycom_epp.c
> @@ -596,7 +596,8 @@ static int receive(struct net_device *dev, int cnt)
>  						state = 0;
>  
>  					/* not flag received */
> -					else if (!(bitstream & (0x1fe << j)) != (0x0fc << j)) {
> +					else if ((bitstream & (0x1fe << j)) !=
> +							(0x0fc << j)) {
>  						if (state)
>  							do_rxpacket(dev);
>  						bc->hdlcrx.bufcnt = 0;

It does look like that is what was intended.

With this fix we're turning on a code path which probably hasn't been
executed by anyone in a decade or so.  I wonder what it'll do?