On Thu, 31 Oct 2024 10:29:51 +0100, Geert Uytterhoeven wrote: > Commit b9bf5612610aa7e3 ("ARM: dts: am335x-bone-common: Increase MDIO > reset deassert time") already increased the MDIO reset deassert delay > from 6.5 to 13 ms, but this may still cause Ethernet PHY probe failures: > > SMSC LAN8710/LAN8720 4a101000.mdio:00: probe with driver SMSC LAN8710/LAN8720 failed with error -5 > > On BeagleBone Black Rev. C3, ETH_RESETn is controlled by an open-drain > AND gate. It is pulled high by a 10K resistor, and has a 4.7µF > capacitor to ground, giving an RC time constant of 47ms. As it takes > 0.7RC to charge the capacitor above the threshold voltage of a CMOS > input (VDD/2), the delay should be at least 33ms. Considering the > typical tolerance of 20% on capacitors, 40ms would be safer. Add an > additional safety margin and settle for 50ms. > > [...] Applied, thanks! [1/1] ARM: dts: am335x-bone-common: Increase MDIO reset deassert delay to 50ms commit: a74a1ada3651c0ff8a05d0ecb74d84de3930e63a Best regards, -- Kevin Hilman <khilman@xxxxxxxxxxxx>