[Backport v3.7-branch] drivers: ethernet: Fix nxp ethernet due to issue in ksz8081 #80923
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500 ms reset time is only for software reset and comes from IEEE spec. Datasheet mentions for hardware reset the assertion of the signal should only need to be 500 us, and 100 us after deassert to wait to access programming interface. Also remove an unused macro. Signed-off-by: Declan Snyder <[email protected]> (cherry picked from commit 9687773)
I for the life of me do not know what is going on here with the RNB chip but it seems this override must be set in order for the chip to work, regardless of strap-in configuration, and if not set explicitly, the value after a reset for these two bits will be seemingly random and inconsistent. And it was working before by luck before removing a second redundant reset in a recent commit, because apparently the register was getting the opposite of the reset value according to the datasheet which makes it work. The result of these bits after reset seem to vary depending on host mcu, board, debugger, number of times reset, type of reset, and with a pinch of random chance after keeping all variables seemingly the same, so let's just set it to the value that works explicitly, even if it doesn't make sense. The bit here doesn't have clear documentation but it seems it's for using RMII regardless of the strap in option, which is what we want to do anyways if we know the interface type from DT, so I think it's fine, considering it is making this driver work again. Signed-off-by: Declan Snyder <[email protected]> (cherry picked from commit 495a374)
jukkar
approved these changes
Nov 6, 2024
pdgendt
approved these changes
Nov 6, 2024
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Backport 495a374~2..495a374 from #80645.
Fixes #79965