| Message ID | 20220728145252.439201-4-maxime.chevallier@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: Introduce QUSGMII phy mode | expand |
> +int phy_interface_num_ports(phy_interface_t interface) > +{ > + switch (interface) { > + case PHY_INTERFACE_MODE_NA: > + case PHY_INTERFACE_MODE_INTERNAL: > + return 0; I've not yet looked at how this is used. Returning 0 could have interesting effects i guess? INTERNAL clearly does have some sort of path between the MAC and the PHY, so i think 1 would be a better value. NA is less clear, it generally means Don't touch. But again, there still needs to be a path between the MAC and PHY, otherwise there would not be any to touch. Why did you pick 0? > + > + case PHY_INTERFACE_MODE_MII: > + case PHY_INTERFACE_MODE_GMII: > + case PHY_INTERFACE_MODE_TBI: > + case PHY_INTERFACE_MODE_REVMII: > + case PHY_INTERFACE_MODE_RMII: > + case PHY_INTERFACE_MODE_REVRMII: > + case PHY_INTERFACE_MODE_RGMII: > + case PHY_INTERFACE_MODE_RGMII_ID: > + case PHY_INTERFACE_MODE_RGMII_RXID: > + case PHY_INTERFACE_MODE_RGMII_TXID: > + case PHY_INTERFACE_MODE_RTBI: > + case PHY_INTERFACE_MODE_XGMII: > + case PHY_INTERFACE_MODE_XLGMII: > + case PHY_INTERFACE_MODE_MOCA: > + case PHY_INTERFACE_MODE_TRGMII: > + case PHY_INTERFACE_MODE_USXGMII: > + case PHY_INTERFACE_MODE_SGMII: > + case PHY_INTERFACE_MODE_SMII: > + case PHY_INTERFACE_MODE_1000BASEX: > + case PHY_INTERFACE_MODE_2500BASEX: > + case PHY_INTERFACE_MODE_5GBASER: > + case PHY_INTERFACE_MODE_10GBASER: > + case PHY_INTERFACE_MODE_25GBASER: > + case PHY_INTERFACE_MODE_10GKR: > + case PHY_INTERFACE_MODE_100BASEX: > + case PHY_INTERFACE_MODE_RXAUI: > + case PHY_INTERFACE_MODE_XAUI: > + return 1; > + case PHY_INTERFACE_MODE_QSGMII: > + case PHY_INTERFACE_MODE_QUSGMII: > + return 4; > + > + default: > + return 0; > + } > +} Have you tried without a default: ? I _think_ gcc will then warn about missing enum values, which will help future developers when they add further values to the enum. Andrew
On 7/28/22 14:32, Andrew Lunn wrote: >> +int phy_interface_num_ports(phy_interface_t interface) >> +{ >> + switch (interface) { >> + case PHY_INTERFACE_MODE_NA: >> + case PHY_INTERFACE_MODE_INTERNAL: >> + return 0; > > I've not yet looked at how this is used. Returning 0 could have > interesting effects i guess? INTERNAL clearly does have some sort of > path between the MAC and the PHY, so i think 1 would be a better > value. NA is less clear, it generally means Don't touch. But again, > there still needs to be a path between the MAC and PHY, otherwise > there would not be any to touch. > > Why did you pick 0? I would agree that returning 1 is a more sensible default to avoid breaking users of that function. However this makes me wonder, in what case will we break the following common meaning: - Q -> quad - P -> penta - O -> octal Is the helper really needed in the sense that the phy_interface_t enumeration is explicit enough thanks to or because of its name? -- Florian
Hello Florian, Andrew, On Thu, 28 Jul 2022 14:44:47 -0700 Florian Fainelli <f.fainelli@gmail.com> wrote: > On 7/28/22 14:32, Andrew Lunn wrote: > >> +int phy_interface_num_ports(phy_interface_t interface) > >> +{ > >> + switch (interface) { > >> + case PHY_INTERFACE_MODE_NA: > >> + case PHY_INTERFACE_MODE_INTERNAL: > >> + return 0; > > > > I've not yet looked at how this is used. Returning 0 could have > > interesting effects i guess? INTERNAL clearly does have some sort of > > path between the MAC and the PHY, so i think 1 would be a better > > value. NA is less clear, it generally means Don't touch. But again, > > there still needs to be a path between the MAC and PHY, otherwise > > there would not be any to touch. > > > > Why did you pick 0? My reasonning was that PHY_INTERNAL is likely a custom solution to link IPs existing on the same die, so nothing prevents vendors from multiplexing links on that interface. But it's a far-fetched reasonning, so 1 can be good, as other interfaces that are meant to be used on-die like XGMII. > I would agree that returning 1 is a more sensible default to avoid > breaking users of that function. However this makes me wonder, in > what case will we break the following common meaning: > > - Q -> quad > - P -> penta > - O -> octal > > Is the helper really needed in the sense that the phy_interface_t > enumeration is explicit enough thanks to or because of its name? -- > Florian Good question actually ! It started as a point from Russell proposing a helper to get the number of serdes lanes for a given interface, but this sisn't quite fit the use-case, which was simply to simplify if (interface == PHY_INTERFACE_MODE_QSGMII || interface == PHY_INTERFACE_MODE_QUSGMII) into if (phy_interface_num_ports(interface) == 4) But this a slim simplification at the cost of a new helper to maintain, so I can repove that if you want. Thanks for the reviews, Maxime
On Thu, 28 Jul 2022 23:32:36 +0200 Andrew Lunn <andrew@lunn.ch> wrote: > > +int phy_interface_num_ports(phy_interface_t interface) > > +{ > > + switch (interface) { > > + case PHY_INTERFACE_MODE_NA: > > + case PHY_INTERFACE_MODE_INTERNAL: > > + return 0; > > I've not yet looked at how this is used. Returning 0 could have > interesting effects i guess? INTERNAL clearly does have some sort of > path between the MAC and the PHY, so i think 1 would be a better > value. NA is less clear, it generally means Don't touch. But again, > there still needs to be a path between the MAC and PHY, otherwise > there would not be any to touch. > > Why did you pick 0? > > > + > > + case PHY_INTERFACE_MODE_MII: > > + case PHY_INTERFACE_MODE_GMII: > > + case PHY_INTERFACE_MODE_TBI: > > + case PHY_INTERFACE_MODE_REVMII: > > + case PHY_INTERFACE_MODE_RMII: > > + case PHY_INTERFACE_MODE_REVRMII: > > + case PHY_INTERFACE_MODE_RGMII: > > + case PHY_INTERFACE_MODE_RGMII_ID: > > + case PHY_INTERFACE_MODE_RGMII_RXID: > > + case PHY_INTERFACE_MODE_RGMII_TXID: > > + case PHY_INTERFACE_MODE_RTBI: > > + case PHY_INTERFACE_MODE_XGMII: > > + case PHY_INTERFACE_MODE_XLGMII: > > + case PHY_INTERFACE_MODE_MOCA: > > + case PHY_INTERFACE_MODE_TRGMII: > > + case PHY_INTERFACE_MODE_USXGMII: > > + case PHY_INTERFACE_MODE_SGMII: > > + case PHY_INTERFACE_MODE_SMII: > > + case PHY_INTERFACE_MODE_1000BASEX: > > + case PHY_INTERFACE_MODE_2500BASEX: > > + case PHY_INTERFACE_MODE_5GBASER: > > + case PHY_INTERFACE_MODE_10GBASER: > > + case PHY_INTERFACE_MODE_25GBASER: > > + case PHY_INTERFACE_MODE_10GKR: > > + case PHY_INTERFACE_MODE_100BASEX: > > + case PHY_INTERFACE_MODE_RXAUI: > > + case PHY_INTERFACE_MODE_XAUI: > > + return 1; > > + case PHY_INTERFACE_MODE_QSGMII: > > + case PHY_INTERFACE_MODE_QUSGMII: > > + return 4; > > + > > + default: > > + return 0; > > + } > > +} > > Have you tried without a default: ? I _think_ gcc will then warn about > missing enum values, which will help future developers when they add > further values to the enum. Without the default clause, I get an error about the missing PHY_INTERFACE_MODE_MAX case, which I don't think belongs here... Too bad :/ > Andrew
On Fri, Jul 29, 2022 at 09:32:52AM +0200, Maxime Chevallier wrote: > On Thu, 28 Jul 2022 23:32:36 +0200 > Andrew Lunn <andrew@lunn.ch> wrote: > > > > +int phy_interface_num_ports(phy_interface_t interface) > > > +{ > > > + switch (interface) { > > > + case PHY_INTERFACE_MODE_NA: > > > + case PHY_INTERFACE_MODE_INTERNAL: > > > + return 0; > > > > I've not yet looked at how this is used. Returning 0 could have > > interesting effects i guess? INTERNAL clearly does have some sort of > > path between the MAC and the PHY, so i think 1 would be a better > > value. NA is less clear, it generally means Don't touch. But again, > > there still needs to be a path between the MAC and PHY, otherwise > > there would not be any to touch. > > > > Why did you pick 0? > > > > > + > > > + case PHY_INTERFACE_MODE_MII: > > > + case PHY_INTERFACE_MODE_GMII: > > > + case PHY_INTERFACE_MODE_TBI: > > > + case PHY_INTERFACE_MODE_REVMII: > > > + case PHY_INTERFACE_MODE_RMII: > > > + case PHY_INTERFACE_MODE_REVRMII: > > > + case PHY_INTERFACE_MODE_RGMII: > > > + case PHY_INTERFACE_MODE_RGMII_ID: > > > + case PHY_INTERFACE_MODE_RGMII_RXID: > > > + case PHY_INTERFACE_MODE_RGMII_TXID: > > > + case PHY_INTERFACE_MODE_RTBI: > > > + case PHY_INTERFACE_MODE_XGMII: > > > + case PHY_INTERFACE_MODE_XLGMII: > > > + case PHY_INTERFACE_MODE_MOCA: > > > + case PHY_INTERFACE_MODE_TRGMII: > > > + case PHY_INTERFACE_MODE_USXGMII: > > > + case PHY_INTERFACE_MODE_SGMII: > > > + case PHY_INTERFACE_MODE_SMII: > > > + case PHY_INTERFACE_MODE_1000BASEX: > > > + case PHY_INTERFACE_MODE_2500BASEX: > > > + case PHY_INTERFACE_MODE_5GBASER: > > > + case PHY_INTERFACE_MODE_10GBASER: > > > + case PHY_INTERFACE_MODE_25GBASER: > > > + case PHY_INTERFACE_MODE_10GKR: > > > + case PHY_INTERFACE_MODE_100BASEX: > > > + case PHY_INTERFACE_MODE_RXAUI: > > > + case PHY_INTERFACE_MODE_XAUI: > > > + return 1; > > > + case PHY_INTERFACE_MODE_QSGMII: > > > + case PHY_INTERFACE_MODE_QUSGMII: > > > + return 4; > > > + > > > + default: > > > + return 0; > > > + } > > > +} > > > > Have you tried without a default: ? I _think_ gcc will then warn about > > missing enum values, which will help future developers when they add > > further values to the enum. > > Without the default clause, I get an error about the missing > PHY_INTERFACE_MODE_MAX case, which I don't think belongs here... case PHY_INTERFACE_MODE_MAX: WARN_ONCE() return 0; break; Being passed PHY_INTERFACE_MODE_MAX is a bug in itself, so warning seems sensible. Andrew
diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c index 1f2531a1a876..6029583f367d 100644 --- a/drivers/net/phy/phy-core.c +++ b/drivers/net/phy/phy-core.c @@ -74,6 +74,58 @@ const char *phy_duplex_to_str(unsigned int duplex) } EXPORT_SYMBOL_GPL(phy_duplex_to_str); +/** + * phy_interface_num_ports - Return the number of links that can be carried by + * a given MAC-PHY physical link. Returns 0 if this is + * unknown, the number of links else. + * + * @interface: The interface mode we want to get the number of ports + */ +int phy_interface_num_ports(phy_interface_t interface) +{ + switch (interface) { + case PHY_INTERFACE_MODE_NA: + case PHY_INTERFACE_MODE_INTERNAL: + return 0; + + case PHY_INTERFACE_MODE_MII: + case PHY_INTERFACE_MODE_GMII: + case PHY_INTERFACE_MODE_TBI: + case PHY_INTERFACE_MODE_REVMII: + case PHY_INTERFACE_MODE_RMII: + case PHY_INTERFACE_MODE_REVRMII: + case PHY_INTERFACE_MODE_RGMII: + case PHY_INTERFACE_MODE_RGMII_ID: + case PHY_INTERFACE_MODE_RGMII_RXID: + case PHY_INTERFACE_MODE_RGMII_TXID: + case PHY_INTERFACE_MODE_RTBI: + case PHY_INTERFACE_MODE_XGMII: + case PHY_INTERFACE_MODE_XLGMII: + case PHY_INTERFACE_MODE_MOCA: + case PHY_INTERFACE_MODE_TRGMII: + case PHY_INTERFACE_MODE_USXGMII: + case PHY_INTERFACE_MODE_SGMII: + case PHY_INTERFACE_MODE_SMII: + case PHY_INTERFACE_MODE_1000BASEX: + case PHY_INTERFACE_MODE_2500BASEX: + case PHY_INTERFACE_MODE_5GBASER: + case PHY_INTERFACE_MODE_10GBASER: + case PHY_INTERFACE_MODE_25GBASER: + case PHY_INTERFACE_MODE_10GKR: + case PHY_INTERFACE_MODE_100BASEX: + case PHY_INTERFACE_MODE_RXAUI: + case PHY_INTERFACE_MODE_XAUI: + return 1; + case PHY_INTERFACE_MODE_QSGMII: + case PHY_INTERFACE_MODE_QUSGMII: + return 4; + + default: + return 0; + } +} +EXPORT_SYMBOL_GPL(phy_interface_num_ports); + /* A mapping of all SUPPORTED settings to speed/duplex. This table * must be grouped by speed and sorted in descending match priority * - iow, descending speed. diff --git a/include/linux/phy.h b/include/linux/phy.h index 6b96b810a4d8..77e4b60bb9ab 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -967,6 +967,8 @@ struct phy_fixup { const char *phy_speed_to_str(int speed); const char *phy_duplex_to_str(unsigned int duplex); +int phy_interface_num_ports(phy_interface_t interface); + /* A structure for mapping a particular speed and duplex * combination to a particular SUPPORTED and ADVERTISED value */
Some phy modes such as QSGMII multiplex several MAC<->PHY links on one single physical interface. QSGMII used to be the only one supported, but other modes such as QUSGMII also carry multiple links. This helper allows getting the number of links that are multiplexed on a given interface. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> --- V1->V2 : New patch drivers/net/phy/phy-core.c | 52 ++++++++++++++++++++++++++++++++++++++ include/linux/phy.h | 2 ++ 2 files changed, 54 insertions(+)