kernel.git/net/dsa/port.c, branch linux-5.7.y

net: dsa: Down cpu/dsa ports phylink will control

2020-04-14T23:33:26Z

DSA and CPU ports can be configured in two ways. By default, the driver should configure such ports to there maximum bandwidth. For most use cases, this is sufficient. When this default is insufficient, a phylink instance can be bound to such ports, and phylink will configure the port, e.g. based on fixed-link properties. phylink assumes the port is initially down. Given that the driver should have already configured it to its maximum speed, ask the driver to down the port before instantiating the phylink instance. Fixes: 30c4a5b0aad8 ("net: mv88e6xxx: use resolved link config in mac_link_up()") Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller

net: dsa: configure the MTU for switch ports

2020-03-27T23:07:24Z

It is useful be able to configure port policers on a switch to accept frames of various sizes: - Increase the MTU for better throughput from the default of 1500 if it is known that there is no 10/100 Mbps device in the network. - Decrease the MTU to limit the latency of high-priority frames under congestion, or work around various network segments that add extra headers to packets which can't be fragmented. For DSA slave ports, this is mostly a pass-through callback, called through the regular ndo ops and at probe time (to ensure consistency across all supported switches). The CPU port is called with an MTU equal to the largest configured MTU of the slave ports. The assumption is that the user might want to sustain a bidirectional conversation with a partner over any switch port. The DSA master is configured the same as the CPU port, plus the tagger overhead. Since the MTU is by definition L2 payload (sans Ethernet header), it is up to each individual driver to figure out if it needs to do anything special for its frame tags on the CPU port (it shouldn't except in special cases). So the MTU does not contain the tagger overhead on the CPU port. However the MTU of the DSA master, minus the tagger overhead, is used as a proxy for the MTU of the CPU port, which does not have a net device. This is to avoid uselessly calling the .change_mtu function on the CPU port when nothing should change. So it is safe to assume that the DSA master and the CPU port MTUs are apart by exactly the tagger's overhead in bytes. Some changes were made around dsa_master_set_mtu(), function which was now removed, for 2 reasons: - dev_set_mtu() already calls dev_validate_mtu(), so it's redundant to do the same thing in DSA - __dev_set_mtu() returns 0 if ops->ndo_change_mtu is an absent method That is to say, there's no need for this function in DSA, we can safely call dev_set_mtu() directly, take the rtnl lock when necessary, and just propagate whatever errors get reported (since the user probably wants to be informed). Some inspiration (mainly in the MTU DSA notifier) was taken from a vaguely similar patch from Murali and Florian, who are credited as co-developers down below. Co-developed-by: Murali Krishna Policharla Signed-off-by: Murali Krishna Policharla Co-developed-by: Florian Fainelli Signed-off-by: Florian Fainelli Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: warn if phylink_mac_link_state returns error

2020-03-16T00:11:12Z

Issue a warning to the kernel log if phylink_mac_link_state() returns an error. This should not occur, but let's make it visible. Signed-off-by: Russell King Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-03-13T05:34:48Z

Minor overlapping changes, nothing serious. Signed-off-by: David S. Miller

net: dsa: Don't instantiate phylink for CPU/DSA ports unless needed

2020-03-12T06:46:11Z

By default, DSA drivers should configure CPU and DSA ports to their maximum speed. In many configurations this is sufficient to make the link work. In some cases it is necessary to configure the link to run slower, e.g. because of limitations of the SoC it is connected to. Or back to back PHYs are used and the PHY needs to be driven in order to establish link. In this case, phylink is used. Only instantiate phylink if it is required. If there is no PHY, or no fixed link properties, phylink can upset a link which works in the default configuration. Fixes: 0e27921816ad ("net: dsa: Use PHYLINK for the CPU/DSA ports") Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller

net: dsa: fix phylink_start()/phylink_stop() calls

2020-03-03T23:45:49Z

Place phylink_start()/phylink_stop() inside dsa_port_enable() and dsa_port_disable(), which ensures that we call phylink_stop() before tearing down phylink - which is a documented requirement. Failure to do so can cause use-after-free bugs. Fixes: 0e27921816ad ("net: dsa: Use PHYLINK for the CPU/DSA ports") Signed-off-by: Russell King Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller

net: dsa: propagate resolved link config via mac_link_up()

2020-02-27T20:02:14Z

Propagate the resolved link configuration down via DSA's phylink_mac_link_up() operation to allow split PCS/MAC to work. Tested-by: Vladimir Oltean Signed-off-by: Russell King Signed-off-by: David S. Miller

net: phylink: propagate resolved link config via mac_link_up()

2020-02-27T20:02:14Z

Propagate the resolved link parameters via the mac_link_up() call for MACs that do not automatically track their PCS state. We propagate the link parameters via function arguments so that inappropriate members of struct phylink_link_state can't be accessed, and creating a new structure just for this adds needless complexity to the API. Tested-by: Andre Przywara Tested-by: Alexandre Belloni Tested-by: Vladimir Oltean Signed-off-by: Russell King Signed-off-by: David S. Miller

net: dsa: Pass pcs_poll flag from driver to PHYLINK

2020-01-06T07:22:32Z

The DSA drivers that implement .phylink_mac_link_state should normally register an interrupt for the PCS, from which they should call phylink_mac_change(). However not all switches implement this, and those who don't should set this flag in dsa_switch in the .setup callback, so that PHYLINK will poll for a few ms until the in-band AN link timer expires and the PCS state settles. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: Make PHYLINK related function static again

2019-12-17T22:17:46Z

Commit 77373d49de22 ("net: dsa: Move the phylink driver calls into port.c") moved and exported a bunch of symbols, but they are not used outside of net/dsa/port.c at the moment, so no reason to export them. Reported-by: Russell King Signed-off-by: Florian Fainelli Reviewed-by: Vivien Didelot Acked-by: Russell King Acked-by: Vladimir Oltean Signed-off-by: David S. Miller