From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH v3 7/9] net: mvmdio: add xmdio xsmi support Date: Mon, 12 Jun 2017 11:17:39 +0100 Message-ID: <20170612101739.GA4902@n2100.armlinux.org.uk> References: <20170612095745.11300-1-antoine.tenart@free-electrons.com> <20170612095745.11300-8-antoine.tenart@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, jason@lakedaemon.net, andrew@lunn.ch, gregory.clement@free-electrons.com, sebastian.hesselbarth@gmail.com, f.fainelli@gmail.com, thomas.petazzoni@free-electrons.com, nadavh@marvell.com, mw@semihalf.com, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: Antoine Tenart Return-path: Received: from pandora.armlinux.org.uk ([78.32.30.218]:36722 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752065AbdFLKSA (ORCPT ); Mon, 12 Jun 2017 06:18:00 -0400 Content-Disposition: inline In-Reply-To: <20170612095745.11300-8-antoine.tenart@free-electrons.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Jun 12, 2017 at 11:57:43AM +0200, Antoine Tenart wrote: > +static const struct orion_mdio_ops *orion_mdio_get_ops(struct orion_mdio_dev *dev, > + int regnum) > +{ > + if (dev->bus_type == BUS_TYPE_XSMI && (regnum & MII_ADDR_C45)) > + return &orion_mdio_xsmi_ops; > + else if (dev->bus_type == BUS_TYPE_SMI) > + return &orion_mdio_smi_ops; > + > + return ERR_PTR(-EOPNOTSUPP); > +} Oh, this is where you're doing it - I'm not sure having this complexity is really necessary - there is no dynamic choice between the two. This seems to be way over-engineered. You might as well make the SMI operations fail if MII_ADDR_C45 is set, and the XSMI operations fail if MII_ADDR_C45 is not set. Hmm, I think this whole driver is over-engineered: 1. the mdio read/write functions implement their own locking. At the MDIO level, there is already locking in the form of a per-bus lock "bus->mdio_lock" which will be taken whenever either of these functions is called. So the driver's "dev->lock" is redundant. 2. with the redundant locking removed, orion_mdio_write() becomes a call to orion_mdio_wait_ready() followed by a call to dev->ops->write. It seems that orion_mdio_wait_ready() could be a library function shared between a SMI version of orion_mdio_write() and a XSMI version. 3. the same is really true of orion_mdio_read(), although that function is a little more complex in itself, the result would actually end up being simpler. With those changes together, it elimates "struct orion_mdio_ops" entirely, and I think makes the driver smaller, simpler, and cleaner. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.