RE: [EXT] Re: [PATCH net-next 0/1] net: fec: add C45 MDIO read/write support
From: Andrew Lunn Sent: Tuesday, August 20, 2019 9:04 PM > On Tue, Aug 20, 2019 at 02:32:26AM +, Andy Duan wrote: > > From: Andrew Lunn > > > On Mon, Aug 19, 2019 at 05:11:14PM +, 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 It still trigger an interrupt to wakeup the completion, we have to wait FEC_MII_TIMEOUT. Older chips just support part of C45 feature just like the patch implementation.
Re: [EXT] Re: [PATCH net-next 0/1] net: fec: add C45 MDIO read/write support
On Tue, Aug 20, 2019 at 02:32:26AM +, Andy Duan wrote: > From: Andrew Lunn > > On Mon, Aug 19, 2019 at 05:11:14PM +, 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
RE: [EXT] Re: [PATCH net-next 0/1] net: fec: add C45 MDIO read/write support
From: Andrew Lunn > On Mon, Aug 19, 2019 at 05:11:14PM +, 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. Andy
