kernel/linux.git/drivers/net/phy/phy-core.c, branch v6.1.168

net: phy: Add support for rate matching

2022-09-23T10:55:35+00:00

This adds support for rate matching (also known as rate adaptation) to the phy subsystem. The general idea is that the phy interface runs at one speed, and the MAC throttles the rate at which it sends packets to the link speed. There's a good overview of several techniques for achieving this at [1]. This patch adds support for three: pause-frame based (such as in Aquantia phys), CRS-based (such as in 10PASS-TS and 2BASE-TL), and open-loop-based (such as in 10GBASE-W). This patch makes a few assumptions and a few non assumptions about the types of rate matching available. First, it assumes that different phys may use different forms of rate matching. Second, it assumes that phys can use rate matching for any of their supported link speeds (e.g. if a phy supports 10BASE-T and XGMII, then it can adapt XGMII to 10BASE-T). Third, it does not assume that all interface modes will use the same form of rate matching. Fourth, it does not assume that all phy devices will support rate matching (even if some do). Relaxing or strengthening these (non-)assumptions could result in a different API. For example, if all interface modes were assumed to use the same form of rate matching, then a bitmask of interface modes supportting rate matching would suffice. For some better visibility into the process, the current rate matching mode is exposed as part of the ethtool ksettings. For the moment, only read access is supported. I'm not sure what userspace might want to configure yet (disable it altogether, disable just one mode, specify the mode to use, etc.). For the moment, since only pause-based rate adaptation support is added in the next few commits, rate matching can be disabled altogether by adjusting the advertisement. 802.3 calls this feature "rate adaptation" in clause 49 (10GBASE-R) and "rate matching" in clause 61 (10PASS-TL and 2BASE-TS). Aquantia also calls this feature "rate adaptation". I chose "rate matching" because it is shorter, and because Russell doesn't think "adaptation" is correct in this context. Signed-off-by: Sean Anderson Signed-off-by: David S. Miller

net: phy: Add 1000BASE-KX interface mode

2022-09-05T13:30:42+00:00

Add 1000BASE-KX interface mode. This 1G backplane ethernet as described in clause 70. Clause 73 autonegotiation is mandatory, and only full duplex operation is supported. Although at the PMA level this interface mode is identical to 1000BASE-X, it uses a different form of in-band autonegation. This justifies a separate interface mode, since the interface mode (along with the MLO_AN_* autonegotiation mode) sets the type of autonegotiation which will be used on a link. This results in more than just electrical differences between the link modes. With regard to 1000BASE-X, 1000BASE-KX holds a similar position to SGMII: same signaling, but different autonegotiation. PCS drivers (which typically handle in-band autonegotiation) may only support 1000BASE-X, and not 1000BASE-KX. Similarly, the phy mode is used to configure serdes phys with phy_set_mode_ext. Due to the different electrical standards (SFI or XFI vs Clause 70), they will likely want to use different configuration. Adding a phy interface mode for 1000BASE-KX helps simplify configuration in these areas. Signed-off-by: Sean Anderson Signed-off-by: David S. Miller

net: phy: Add helper to derive the number of ports from a phy mode

2022-08-22T12:46:26+00:00

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 Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller

ethtool: Add 10base-T1L link mode entry

2022-05-01T16:45:35+00:00

Add entry for the 10base-T1L full duplex mode. Reviewed-by: Andrew Lunn Reviewed-by: Oleksij Rempel Signed-off-by: Alexandru Tachici Signed-off-by: David S. Miller

phy: make phy_set_max_speed() void

2022-01-31T11:30:56+00:00

After following the call tree of phy_set_max_speed(), it became clear that this function never returns anything but 0, so we can change its result type to *void* and drop the result checks from the three drivers that actually bothered to do it... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Signed-off-by: Sergey Shtylyov Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller

net: phy: prefer 1000baseT over 1000baseKX

2021-12-09T19:51:50+00:00

The PHY settings table is supposed to be sorted by descending match priority - in other words, earlier entries are preferred over later entries. The order of 1000baseKX/Full and 1000baseT/Full is such that we prefer 1000baseKX/Full over 1000baseT/Full, but 1000baseKX/Full is a lot rarer than 1000baseT/Full, and thus is much less likely to be preferred. This causes phylink problems - it means a fixed link specifying a speed of 1G and full duplex gets an ethtool linkmode of 1000baseKX/Full rather than 1000baseT/Full as would be expected - and since we offer userspace a software emulation of a conventional copper PHY, we want to offer copper modes in preference to anything else. However, we do still want to allow the rarer modes as well. Hence, let's reorder these two modes to prefer copper. Tested-by: Tom Lendacky Signed-off-by: Russell King (Oracle) Reviewed-by: Andrew Lunn Reported-by: Florian Fainelli Link: https://lore.kernel.org/r/E1muvFO-00F6jY-1K@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski

net: phy: correct format of block comments

2021-06-16T19:34:07+00:00

Block comments should not use a trailing */ on a separate line and every line of a block comment should start with an '*'. Signed-off-by: Wenpeng Liang Signed-off-by: Weihang Li Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller

net: phy: Document core PHY structures

2020-09-24T01:02:49+00:00

Add kerneldoc for the core PHY data structures, a few inline functions and exported functions which are not already documented. v2 Typos g/phy/PHY/s Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller

ethtool: Add 100base-FX link mode entries

2020-09-19T23:54:35+00:00

Add entries for the 100base-FX full and half duplex supported modes. $ ethtool eth0 Supported ports: [ FIBRE ] Supported link modes: 100baseFX/Half 100baseFX/Full Supported pause frame use: Symmetric Receive-only Supports auto-negotiation: No Supported FEC modes: Not reported Advertised link modes: 100baseFX/Half 100baseFX/Full Advertised pause frame use: No Advertised auto-negotiation: No Advertised FEC modes: Not reported Speed: 100Mb/s Duplex: Full Auto-negotiation: off Port: MII PHYAD: 1 Transceiver: external Supports Wake-on: gs Wake-on: d SecureOn password: 00:00:00:00:00:00 Current message level: 0x00000000 (0) Link detected: yes Signed-off-by: Dan Murphy Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

ethtool: Add support for 100Gbps per lane link modes

2020-07-08T22:30:42+00:00

Define 100G, 200G and 400G link modes using 100Gbps per lane LR, ER and FR are defined as a single link mode because they are using same technology and by design are fully interoperable. EEPROM content indicates if the module is LR, ER, or FR, and the user space ethtool decoder is planned to support decoding these modes in the EEPROM. Signed-off-by: Meir Lichtinger CC: Andrew Lunn Reviewed-by: Aya Levin Signed-off-by: Saeed Mahameed Signed-off-by: David S. Miller