Hello Vladimir, On Fri, Apr 9, 2021 at 12:46 AM Vladimir Oltean <olte...@gmail.com> wrote: > > On Thu, Apr 08, 2021 at 08:38:27PM +0200, Martin Blumenstingl wrote: > > PHY auto polling on the GSWIP hardware can be used so link changes > > (speed, link up/down, etc.) can be detected automatically. Internally > > GSWIP reads the PHY's registers for this functionality. Based on this > > automatic detection GSWIP can also automatically re-configure it's port > > settings. Unfortunately this auto polling (and configuration) mechanism > > seems to cause various issues observed by different people on different > > devices: > > - FritzBox 7360v2: the two Gbit/s ports (connected to the two internal > > PHY11G instances) are working fine but the two Fast Ethernet ports > > (using an AR8030 RMII PHY) are completely dead (neither RX nor TX are > > received). It turns out that the AR8030 PHY sets the BMSR_ESTATEN bit > > as well as the ESTATUS_1000_TFULL and ESTATUS_1000_XFULL bits. This > > makes the PHY auto polling state machine (rightfully?) think that the > > established link speed (when the other side is Gbit/s capable) is > > 1Gbit/s. > > Why do you say "rightfully"? The PHY is gigabit capable, and it reports > that via the Extended Status register. This is one of the reasons why > the "advertising" and "supported" link modes are separate concepts, > because even though you support gigabit, you don't advertise it because > you are in RMII mode. according to the marketing materials of the AR8030 it is a "Ultra low-power single RMII Fast Ethernet PHY" based on that I am referring to this PHY as "not Gbit/s capable" (other PHYs from the AR803x series are Gbit/s capable though)
> How does turning off the auto polling feature help circumvent the > Atheros PHY reporting "issue"? Do we even know that is the problem, or > is it simply a guess on your part based on something that looked strange? I have a patch in my queue (which I'll send for the next -net-next cycle) which adds "ethtool -d" (.get_regs) support to the GSWIP driver. There are multiple status registers, one of them indicates that the link speed (as result of the auto polling mechanism) is 1Gbit/s [...] > > Switch to software based configuration instead of PHY auto polling (and > > letting the GSWIP hardware configure the ports automatically) for the > > following link parameters: > > - link up/down > > - link speed > > - full/half duplex > > - flow control (RX / TX pause) > > What does the auto polling feature consist of, exactly? Is there some > sort of microcontroller accessing the MDIO bus simultaneously with > Linux? I believe the answer is yes, but there's no clear description in the datasheet for a newer GSWIP revision [0] "Figure 8" on page 41 (or page 39 if you go by the numbers at the bottom of each page) has a description of the state machine logic. If I understood Hauke correct the "not fiber" part is only checked for newer GSWIP revisions Please note that the datasheet from [0] refers to part number GSW140 which is a stand-alone IC. The GSWIP driver (currently) supports an older revision (at least two generations older) of GSWIP which is built into Lantiq xRX200 and xRX300 SoCs. Best regards, Martin [0] https://www.maxlinear.com/document/index?id=23266&languageid=1033&type=Datasheet&partnumber=GSW140&filename=617930_GSW140_DS_Rev1.7.pdf&part=GSW140
