From mboxrd@z Thu Jan  1 00:00:00 1970
From: linas@austin.ibm.com (Linas Vepstas)
Subject: Re: spidernet: add improved phy support in sungem_phy.c
Date: Tue, 30 Jan 2007 16:30:50 -0600
Message-ID: <20070130223050.GE5616@austin.ibm.com>
References: <200701261407.48237.jens@de.ibm.com> <1169842847.24996.106.camel@localhost.localdomain> <200701262331.58491.jens@de.ibm.com> <20070126233809.GA16660@electric-eye.fr.zoreil.com>
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Cc: Jens Osterkamp <jens@de.ibm.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Ishizaki Kou <kou.ishizaki@toshiba.co.jp>,
	linuxppc-dev@ozlabs.org, netdev@vger.kernel.org,
	cbe-oss-dev@ozlabs.org, jgarzik@pobox.com,
	James K Lewis <jim@jklewis.com>
To: Francois Romieu <romieu@fr.zoreil.com>
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On Sat, Jan 27, 2007 at 12:38:09AM +0100, Francois Romieu wrote:
> Jens Osterkamp <jens@de.ibm.com> :
> > 
> Index: linux-2.6.20-rc5/drivers/net/sungem_phy.c
> ===================================================================
> --- linux-2.6.20-rc5.orig/drivers/net/sungem_phy.c
> +++ linux-2.6.20-rc5/drivers/net/sungem_phy.c
> @@ -311,6 +311,107 @@ static int bcm5411_init(struct mii_phy* 
> [...]
> +	if ( (phy_reg & 0x0020) >> 5 ) {

Shifting to the right by 5 bits has no effect on the result
of this conditional. Either the bit is set, or its not.
There is no need to shift.

> +	if ( (phy_reg & 0x0020) >> 7 ) {

The result here will always be zero, since the bit,
if set, will be shifted off the end. Bits on the lef
are padded with zero.  Ergo, this is a bug.

--linas