From mboxrd@z Thu Jan 1 00:00:00 1970 From: antoine.tenart@free-electrons.com (Antoine Tenart) Date: Mon, 12 Jun 2017 13:54:35 +0200 Subject: [PATCH v3 7/9] net: mvmdio: add xmdio xsmi support In-Reply-To: <20170612101739.GA4902@n2100.armlinux.org.uk> References: <20170612095745.11300-1-antoine.tenart@free-electrons.com> <20170612095745.11300-8-antoine.tenart@free-electrons.com> <20170612101739.GA4902@n2100.armlinux.org.uk> Message-ID: <20170612115435.GC22312@kwain> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Russell, On Mon, Jun 12, 2017 at 11:17:39AM +0100, Russell King - ARM Linux wrote: > 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're right, there is no dynamic choice between the two. The advantage is the logic of the read/write operations are not duplicated. > 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. This check is already done for xSMI operations. But this should also be the case for SMI ones, you're right. > 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. OK, that's a good rework to add in the series. > 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. I'm not completely convinced as the read and write functions end up being duplicated. One for SMI operations and one for xSMI. But I don't really care, if you think this is better let's go for it. Should I add your first patch in my series and squash the second one in patch 7/9? (I'll also remove the bus_type member from the private struct, as well as the one line it's used in the probe). Thanks! Antoine -- Antoine T?nart, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: not available URL: