Messages in this thread Patch in this message | | | From | Sean Anderson <> | Subject | [PATCH v3 09/11] net: phylink: Adjust advertisement based on rate adaptation | Date | Mon, 25 Jul 2022 11:37:27 -0400 |
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This adds support for adjusting the advertisement for pause-based rate adaptation. This may result in a lossy link, since the final link settings are not adjusted. Asymmetric pause support is necessary. It would be possible for a MAC supporting only symmetric pause to use pause-based rate adaptation, but only if pause reception was enabled as well.
Signed-off-by: Sean Anderson <sean.anderson@seco.com> ---
Changes in v3: - Add phylink_cap_from_speed_duplex to look up the mac capability corresponding to the interface's speed. - Include RATE_ADAPT_CRS; it's a few lines and it doesn't hurt.
Changes in v2: - Determine the interface speed and max mac speed directly instead of guessing based on the caps.
drivers/net/phy/phylink.c | 58 +++++++++++++++++++++++++++++++++++++-- include/linux/phylink.h | 3 +- 2 files changed, 57 insertions(+), 4 deletions(-)
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index 27b60a89ddc6..0eaca6f34413 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -456,14 +456,18 @@ static unsigned long phylink_cap_from_speed_duplex(int speed, * phylink_get_capabilities() - get capabilities for a given MAC * @interface: phy interface mode defined by &typedef phy_interface_t * @mac_capabilities: bitmask of MAC capabilities + * @rate_adaptation: type of rate adaptation being performed * * Get the MAC capabilities that are supported by the @interface mode and * @mac_capabilities. */ unsigned long phylink_get_capabilities(phy_interface_t interface, - unsigned long mac_capabilities) + unsigned long mac_capabilities, + int rate_adaptation) { + int max_speed = phylink_interface_max_speed(interface); unsigned long caps = MAC_SYM_PAUSE | MAC_ASYM_PAUSE; + unsigned long adapted_caps = 0; switch (interface) { case PHY_INTERFACE_MODE_USXGMII: @@ -536,7 +540,53 @@ unsigned long phylink_get_capabilities(phy_interface_t interface, break; } - return caps & mac_capabilities; + switch (rate_adaptation) { + case RATE_ADAPT_OPEN_LOOP: + /* TODO */ + fallthrough; + case RATE_ADAPT_NONE: + adapted_caps = 0; + break; + case RATE_ADAPT_PAUSE: { + /* The MAC must support asymmetric pause towards the local + * device for this. We could allow just symmetric pause, but + * then we might have to renegotiate if the link partner + * doesn't support pause. This is because there's no way to + * accept pause frames without transmitting them if we only + * support symmetric pause. + */ + if (!(mac_capabilities & MAC_SYM_PAUSE) || + !(mac_capabilities & MAC_ASYM_PAUSE)) + break; + + /* We can't adapt if the MAC doesn't support the interface's + * max speed at full duplex. + */ + if (mac_capabilities & + phylink_cap_from_speed_duplex(max_speed, DUPLEX_FULL)) { + /* Although a duplex-adapting phy might exist, we + * conservatively remove these modes because the MAC + * will not be aware of the half-duplex nature of the + * link. + */ + adapted_caps = GENMASK(__fls(caps), __fls(MAC_10HD)); + adapted_caps &= ~(MAC_1000HD | MAC_100HD | MAC_10HD); + } + break; + } + case RATE_ADAPT_CRS: + /* The MAC must support half duplex at the interface's max + * speed. + */ + if (mac_capabilities & + phylink_cap_from_speed_duplex(max_speed, DUPLEX_HALF)) { + adapted_caps = GENMASK(__fls(caps), __fls(MAC_10HD)); + adapted_caps &= mac_capabilities; + } + break; + } + + return (caps & mac_capabilities) | adapted_caps; } EXPORT_SYMBOL_GPL(phylink_get_capabilities); @@ -560,7 +610,8 @@ void phylink_generic_validate(struct phylink_config *config, phylink_set_port_modes(mask); phylink_set(mask, Autoneg); caps = phylink_get_capabilities(state->interface, - config->mac_capabilities); + config->mac_capabilities, + state->rate_adaptation); phylink_caps_to_linkmodes(mask, caps); linkmode_and(supported, supported, mask); @@ -1586,6 +1637,7 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy, config.interface = PHY_INTERFACE_MODE_NA; else config.interface = interface; + config.rate_adaptation = phy_get_rate_adaptation(phy, config.interface); ret = phylink_validate(pl, supported, &config); if (ret) { diff --git a/include/linux/phylink.h b/include/linux/phylink.h index 192a18a8674a..265a344e1039 100644 --- a/include/linux/phylink.h +++ b/include/linux/phylink.h @@ -543,7 +543,8 @@ void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps); int phylink_caps_find_max_speed(unsigned long caps, int *speed, unsigned int *duplex); unsigned long phylink_get_capabilities(phy_interface_t interface, - unsigned long mac_capabilities); + unsigned long mac_capabilities, + int rate_adaptation); void phylink_generic_validate(struct phylink_config *config, unsigned long *supported, struct phylink_link_state *state); -- 2.35.1.1320.gc452695387.dirty
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