On 2024-09-06 22:36:49 +0200, Andrew Lunn wrote: > On Fri, Sep 06, 2024 at 03:39:51PM +0200, Niklas Söderlund wrote: > > The initial marvell-88q2xxx driver only supported the Marvell 88Q2110 > > PHY without auto negotiation support. The reason documented states that > > the provided initialization sequence did not to work. Now a method to > > enable auto negotiation have been found by comparing the initialization > > of other supported devices and an out-of-tree PHY driver. > > > > Perform the minimal needed initialization of the PHY to get auto > > negotiation working and remove the limitation that disables the auto > > negotiation feature for the mv88q2110 device. > > > > With this change a 1000Mbps full duplex link is able to be negotiated > > between two mv88q2110 and the link works perfectly. The other side also > > reflects the manually configure settings of the master device. > > > > # ethtool eth0 > > Settings for eth0: > > Supported ports: [ ] > > Supported link modes: 100baseT1/Full > > 1000baseT1/Full > > Supported pause frame use: Symmetric Receive-only > > Supports auto-negotiation: Yes > > My understanding is that most automotive applications using T1 don't > actually want auto-neg, because it is slow. Given the static use case, > everything can be statically configured. > > Is there a danger this change is going to cause regressions? There are > users who are happy for it to use 100BaseT1 without negotiation, and > the link partner is not offering any sort of negotiation. But with > this change, autoneg is now the default, and the link fails to come > up? I'm not sure how the generic use-case looks like. All I can say all other devices supported by this driver support autoneg by default and the initial commit adds some of the autoneg features but disables it with a comment that they could not get it to work. > > To me, this actually seems like a generic problem for automotive. We > want to indicate the device does support autoneg, but we don't want it > on by default? I don't know if we can express that at the moment? > > Andrew -- Kind Regards, Niklas Söderlund
