On 03.07.19 17:55, Andrew Lunn wrote: > On Wed, Jul 03, 2019 at 03:10:34PM +0200, Benjamin Beckmeyer wrote: >> Hey folks, >> >> I'm having a problem with a custom i.mx6ul board. When DSA is loaded I can't >> get access to the switch via MDIO, but the DSA is working properly. I set up >> a bridge for testing and the switch is in forwarding mode and i can ping the >> board. But the MDIO access isn't working at address 2 for the switch. When I >> delete the DSA from the devicetree and start the board up, I can access the >> switch via MDIO. >> >> With DSA up and running: >> >> mii -i 2 0 0x9800 >> mii -i 2 1 >> phyid:2, reg:0x01 -> 0x4000 >> mii -i 2 0 0x9803 >> mii -i 2 1 >> phyid:2, reg:0x01 -> 0x4000 >> mii -i 2 1 0x1883 >> mii -i 2 1 >> phyid:2, reg:0x01 -> 0x4000 > Hi Benjamin > > I'm guessing that the driver is also using register 0 and 1 at the > same time you are, e.g. to poll the PHYs for link status etc. > > There are trace points for MDIO, so you can get the kernel to log all > registers access. That should confirm if i'm right. > > Andrew
Hi Andrew, you were absolutly right. The bus is really busy the whole time, I've checked that with the tracepoints in mdio_access. But I'm still wondering why isn't that with a single chip addressing mode configured switch? I mean, okay, the switch has more ports, but I've checked the accesses for both. The 6321(single chip addressing mode) has around 4-5 accesses to the MDIO bus and the 6390(multi chip addressing mode) has around 600 accesses per second. Thanks, Benjamin
