From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by casper.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1baHlJ-0006Tr-DD for barebox@lists.infradead.org; Thu, 18 Aug 2016 07:29:14 +0000 Date: Thu, 18 Aug 2016 09:28:52 +0200 From: Sascha Hauer Message-ID: <20160818072852.GK20657@pengutronix.de> References: <20160808193203.13ab931dc3ea505a3cdb2b09@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160808193203.13ab931dc3ea505a3cdb2b09@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: net: phy: fixed link To: Antony Pavlov Cc: barebox@lists.infradead.org On Mon, Aug 08, 2016 at 07:32:03PM +0300, Antony Pavlov wrote: > Hi Sascha! > > I have just took a look on Lukas' > 'net: phy: fixed-link: read link parameters from devicetree' patch. > I see two problems with current 'of_phy_register_fixed_link()' implementation > unrelated to Lukas' changes. > > Please see current of_phy_register_fixed_link() implementation: > > static struct phy_device *of_phy_register_fixed_link(struct device_node *np, > struct eth_device *edev) > { > struct phy_device *phydev; > > phydev = phy_device_create(NULL, 0, 0); > > phydev->dev.parent = &edev->dev; > phydev->registered = 1; > phydev->speed = 1000; > phydev->duplex = 1; > phydev->pause = phydev->asym_pause = 0; > phydev->link = 1; > > return phydev; > } > > 1. (a trivial think) the line > > phydev->link = 1; > > is redundant because phy_device_create() has already set it. Yes, this is redundant and can be removed. > > 2. (not so trivial think) the line > > phydev->registered = 1; > > Why we want to set phydev->registered here? Can we use phy_register_device() instead? If we use phy_register_device() here then I think the genphy driver is attached to the fixed link which probably can't handle this fake device. You can give it a try, but I assume you will see NULL pointer exceptions in several places. phydev->registered = 1 is necessary because without this phy_register_device() is called in phy_device_attach() which is called from phy_device_connect() called from the network device driver. There may be ways to properly register a fixed link as a phy device, but this would mean some serious rework of the phy layer. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox