It was reported that some rb912 boards (ar934x) have issues with some ethernet speeds.
Investigation shows that the board failed to adapt the ethernet pll values as shown here:
[ 5.284359] ag71xx 19000000.eth: failed to read pll-handle property
added custom prints in code and triggering a link switch:
[ 62.821446] Atheros AG71xx: fast reset
[ 62.826442] Atheros AG71xx: update pll 2
[ 62.830494] Atheros AG71xx: no pll regmap!
Comparison with another very similar board (rb922 - QCA955x) showed a missing
reference clock frequency in dts, which seems to cause a pll init issue.
Unfortunately, no errors are printed when this occurs.
Adding the frequency property fixes the pll init as it can be parsed now
by the ethernet driver.
[ 55.861407] Atheros AG71xx: fast reset
[ 55.866403] Atheros AG71xx: update pll 2
[ 55.870462] Atheros AG71xx: ath79_set_pllval: regmap: 0x81548000, pll_reg: 0x2c, pll_val: 0x02000000
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
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