Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
> Another approach could be to maintain a list of modules that do not work > with the generic PHY driver and therefore require a specialized driver, > in that case we could even go as far as not letting sfp_sm_probe_phy() > return success. Not sure how well things would scale, probably not too > bad given there are only a handful of users of the SFP framework thus far... Hi Florian Blacklisting modules with known issues with the generic driver does not sound too bad. This is just a warning, a helpful hint, and it is not going to work anyway. And i don't see scaling problems, Copper SFPs seems quite odd to start with... Andrew
Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
On 11/6/18 4:34 PM, Russell King - ARM Linux wrote: > On Tue, Nov 06, 2018 at 04:09:35PM -0800, Florian Fainelli wrote: >> On 11/6/18 4:03 PM, Russell King - ARM Linux wrote: >>> On Tue, Nov 06, 2018 at 03:38:44PM -0800, David Miller wrote: From: Florian Fainelli Date: Tue, 6 Nov 2018 15:29:10 -0800 > This patch series allows warning an user that the generic PHY driver(s) > are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is > likely not going to work at all. > > Let me know if you would want to do that differently. Is there ever a possibility that the generic PHY driver could work in an SFP situation? >>> >>> I don't yet see the reason for Florian's patch series - all the Marvell >>> 88e based modules I have, or have come across in information from >>> manufacturers self-configure themselves and don't really need the >>> Marvell 1G PHY driver. >>> >>> For example, the Source Photonics were offering a range of 1GbaseT >>> modules with the 88e programmed in different modes, but published >>> instructions for the register accesses to configure them differently >>> (eg, SGMII vs 1000base-X interface facing the MAC). Depending on >>> the module part number determines which mode the PHY has been >>> programmed to come up in. >>> >>> So in theory, you don't need any PHY driver for these modules - but >>> it's useful to have a functional PHY driver to be able to read out >>> the negotiated flow control results. >>> >>> I'd like more information from Florian about the reasoning behind >>> this patch series before it's merged. >>> >> >> The module that I am using [1] would not work, as in , no link up being >> reported without turning on the Marvell PHY driver: >> >> https://www.amazon.com/dp/B01LW2P72V/ref=twister_B07F3WQJQX?_encoding=UTF8&psc=1 >> >> this module uses a 88E PHY as well (OUI: 0x01410cc2). > > From the above URL: > > * This is 1000M SFP-T Transceiver, not 10/100/1000M Multi-Rate SFP-T. If >you want to buy 10/100/1000M Multi-Rate SFP-T, pls contact us.10Gtek >offer more compatible options, if your brands not listed above, pls >contact us. > > I wonder if this is like the Source Photonics situation, where the > 1000base-T only variant of their module uses 1000base-X on the MAC > side, whereas their 10/100/1000base-T variant uses SGMII. The only > difference between these are the part numbers and the programming > of the 88E to tell it which mode to default to for the host > side. (There's no true way to know from the EEPROM whether a module > wants SGMII or 1000base-X.) > > What I also gather is that this is a 10Gtek-manufactured version of > the Ubiquiti UF-RJ45-1G - the original Ubiquiti version supports > 10/100/1G speeds which would require the 88e to configure for > a SGMII host interface by default. > > Now, the reason that modules with an 88E configured to default to > 1000base-X will work when the marvell PHY driver is present, but not > with the generic driver is that the marvell PHY driver will see that > SFP/phylink is wanting to use SGMII mode, and the Marvell PHY driver > reprograms the PHY to use SGMII. This is only a problem for these > modules. > > So, in so far as your patch 3 goes to give a hint that the Marvell > driver should be selected, that's correct. > > However, where the 88e is configured for SGMII by default, the > Marvell driver shouldn't be required, and I wonder whether we ought > to be issuing a warning in that case. The problem, however, is there > is no way to know for certain. > > We could have modules that do not use the Marvell PHY, and if we don't > have a PHY driver for their particular PHY, do we want a warning to be > issued? Another approach could be to maintain a list of modules that do not work with the generic PHY driver and therefore require a specialized driver, in that case we could even go as far as not letting sfp_sm_probe_phy() return success. Not sure how well things would scale, probably not too bad given there are only a handful of users of the SFP framework thus far... > > The whole 1000base-X vs SGMII with SFP modules is all very icky. :( > -- Florian
Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
On Tue, Nov 06, 2018 at 04:09:35PM -0800, Florian Fainelli wrote: > On 11/6/18 4:03 PM, Russell King - ARM Linux wrote: > > On Tue, Nov 06, 2018 at 03:38:44PM -0800, David Miller wrote: > >> From: Florian Fainelli > >> Date: Tue, 6 Nov 2018 15:29:10 -0800 > >> > >>> This patch series allows warning an user that the generic PHY driver(s) > >>> are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is > >>> likely not going to work at all. > >>> > >>> Let me know if you would want to do that differently. > >> > >> Is there ever a possibility that the generic PHY driver could work > >> in an SFP situation? > > > > I don't yet see the reason for Florian's patch series - all the Marvell > > 88e based modules I have, or have come across in information from > > manufacturers self-configure themselves and don't really need the > > Marvell 1G PHY driver. > > > > For example, the Source Photonics were offering a range of 1GbaseT > > modules with the 88e programmed in different modes, but published > > instructions for the register accesses to configure them differently > > (eg, SGMII vs 1000base-X interface facing the MAC). Depending on > > the module part number determines which mode the PHY has been > > programmed to come up in. > > > > So in theory, you don't need any PHY driver for these modules - but > > it's useful to have a functional PHY driver to be able to read out > > the negotiated flow control results. > > > > I'd like more information from Florian about the reasoning behind > > this patch series before it's merged. > > > > The module that I am using [1] would not work, as in , no link up being > reported without turning on the Marvell PHY driver: > > https://www.amazon.com/dp/B01LW2P72V/ref=twister_B07F3WQJQX?_encoding=UTF8&psc=1 > > this module uses a 88E PHY as well (OUI: 0x01410cc2). >From the above URL: * This is 1000M SFP-T Transceiver, not 10/100/1000M Multi-Rate SFP-T. If you want to buy 10/100/1000M Multi-Rate SFP-T, pls contact us.10Gtek offer more compatible options, if your brands not listed above, pls contact us. I wonder if this is like the Source Photonics situation, where the 1000base-T only variant of their module uses 1000base-X on the MAC side, whereas their 10/100/1000base-T variant uses SGMII. The only difference between these are the part numbers and the programming of the 88E to tell it which mode to default to for the host side. (There's no true way to know from the EEPROM whether a module wants SGMII or 1000base-X.) What I also gather is that this is a 10Gtek-manufactured version of the Ubiquiti UF-RJ45-1G - the original Ubiquiti version supports 10/100/1G speeds which would require the 88e to configure for a SGMII host interface by default. Now, the reason that modules with an 88E configured to default to 1000base-X will work when the marvell PHY driver is present, but not with the generic driver is that the marvell PHY driver will see that SFP/phylink is wanting to use SGMII mode, and the Marvell PHY driver reprograms the PHY to use SGMII. This is only a problem for these modules. So, in so far as your patch 3 goes to give a hint that the Marvell driver should be selected, that's correct. However, where the 88e is configured for SGMII by default, the Marvell driver shouldn't be required, and I wonder whether we ought to be issuing a warning in that case. The problem, however, is there is no way to know for certain. We could have modules that do not use the Marvell PHY, and if we don't have a PHY driver for their particular PHY, do we want a warning to be issued? The whole 1000base-X vs SGMII with SFP modules is all very icky. :( -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
On 11/6/18 4:03 PM, Russell King - ARM Linux wrote: > On Tue, Nov 06, 2018 at 03:38:44PM -0800, David Miller wrote: >> From: Florian Fainelli >> Date: Tue, 6 Nov 2018 15:29:10 -0800 >> >>> This patch series allows warning an user that the generic PHY driver(s) >>> are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is >>> likely not going to work at all. >>> >>> Let me know if you would want to do that differently. >> >> Is there ever a possibility that the generic PHY driver could work >> in an SFP situation? > > I don't yet see the reason for Florian's patch series - all the Marvell > 88e based modules I have, or have come across in information from > manufacturers self-configure themselves and don't really need the > Marvell 1G PHY driver. > > For example, the Source Photonics were offering a range of 1GbaseT > modules with the 88e programmed in different modes, but published > instructions for the register accesses to configure them differently > (eg, SGMII vs 1000base-X interface facing the MAC). Depending on > the module part number determines which mode the PHY has been > programmed to come up in. > > So in theory, you don't need any PHY driver for these modules - but > it's useful to have a functional PHY driver to be able to read out > the negotiated flow control results. > > I'd like more information from Florian about the reasoning behind > this patch series before it's merged. > The module that I am using [1] would not work, as in , no link up being reported without turning on the Marvell PHY driver: https://www.amazon.com/dp/B01LW2P72V/ref=twister_B07F3WQJQX?_encoding=UTF8&psc=1 this module uses a 88E PHY as well (OUI: 0x01410cc2). -- Florian
Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
On Tue, Nov 06, 2018 at 03:38:44PM -0800, David Miller wrote: > From: Florian Fainelli > Date: Tue, 6 Nov 2018 15:29:10 -0800 > > > This patch series allows warning an user that the generic PHY driver(s) > > are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is > > likely not going to work at all. > > > > Let me know if you would want to do that differently. > > Is there ever a possibility that the generic PHY driver could work > in an SFP situation? I don't yet see the reason for Florian's patch series - all the Marvell 88e based modules I have, or have come across in information from manufacturers self-configure themselves and don't really need the Marvell 1G PHY driver. For example, the Source Photonics were offering a range of 1GbaseT modules with the 88e programmed in different modes, but published instructions for the register accesses to configure them differently (eg, SGMII vs 1000base-X interface facing the MAC). Depending on the module part number determines which mode the PHY has been programmed to come up in. So in theory, you don't need any PHY driver for these modules - but it's useful to have a functional PHY driver to be able to read out the negotiated flow control results. I'd like more information from Florian about the reasoning behind this patch series before it's merged. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
On 11/6/18 3:38 PM, David Miller wrote: > From: Florian Fainelli > Date: Tue, 6 Nov 2018 15:29:10 -0800 > >> This patch series allows warning an user that the generic PHY driver(s) >> are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is >> likely not going to work at all. >> >> Let me know if you would want to do that differently. > > Is there ever a possibility that the generic PHY driver could work > in an SFP situation? Given the PHY has to operate in SGMII mode, I doubt it could work without a specialized driver, Andrew, Russell, would you concur? > > If not, yes emit the message but also fail the load and registry too > perhaps? > I was not sure this would be acceptable, but it is definitively an easy change. -- Florian
Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver
From: Florian Fainelli Date: Tue, 6 Nov 2018 15:29:10 -0800 > This patch series allows warning an user that the generic PHY driver(s) > are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is > likely not going to work at all. > > Let me know if you would want to do that differently. Is there ever a possibility that the generic PHY driver could work in an SFP situation? If not, yes emit the message but also fail the load and registry too perhaps?
