Messages in this thread | | | Date | Tue, 20 Aug 2019 15:04:03 +0200 | From | Andrew Lunn <> | Subject | Re: [EXT] Re: [PATCH net-next 0/1] net: fec: add C45 MDIO read/write support |
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On Tue, Aug 20, 2019 at 02:32:26AM +0000, Andy Duan wrote: > From: Andrew Lunn <andrew@lunn.ch> > > On Mon, Aug 19, 2019 at 05:11:14PM +0000, Marco Hartmann wrote: > > > As of yet, the Fast Ethernet Controller (FEC) driver only supports > > > Clause 22 conform MDIO transactions. IEEE 802.3ae Clause 45 defines a > > > modified MDIO protocol that uses a two staged access model in order to > > > increase the address space. > > > > > > This patch adds support for Clause 45 conform MDIO read and write > > > operations to the FEC driver. > > > > Hi Marco > > > > Do all versions of the FEC hardware support C45? Or do we need to make use > > of the quirk support in this driver to just enable it for some revisions of FEC? > > > > Thanks > > Andrew > > i.MX legacy platforms like i.MX6/7 series, they doesn't support Write & Read Increment. > But for i.MX8MQ/MM series, it support C45 full features like Write & Read Increment. > > For the patch itself, it doesn't support Write & Read Increment, so I think the patch doesn't > need to add quirk support.
Hi Andy
So what happens with something older than a i.MX8MQ/MM when a C45 transfer is attempted? This patch adds a new write. Does that write immediately trigger a completion interrupt? Does it never trigger an interrupt, and we have to wait FEC_MII_TIMEOUT?
Ideally, if the hardware does not support C45, we want it to return EOPNOTSUPP.
Thanks Andrew
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